@Babyrat: I believe in the use of manga to improve one's reading, vocab, etc. So I'm dumping this list on you. 
Golden Time (ゴールデンタイム)
Difficulty: ***
Description: Tada Banri lost all of his memories just as he was about to graduate from high school. One year later, on the way to his law school entrance ceremony, he meets Kaga Kouko, who is beating the guy he just met with a bouquet or roses. By the author of ToraDora! Manga version of the novels. (Great story, IMO.)
Text: Medium.
Furigana: YES! (If you read the books/manga, you may get this joke!)
Hayate no Gotoku (ハヤテのごとく！)
Difficulty: **, sometimes *** when it gets all "plotty," but that's not often. This was the first manga I bought in Japanese, and could muddle through it with basic skills. You can get by with * skill even, if you're patient.
Description: Ayasaki Hayate is sold to the yakuza by his parents to settle a 150M yen debt, then is saved by 13 year-old Sanzenin Nagi, who falls for him even though he tries to kidnap her (she misunderstands), then he becomes her butler, and 400+ chapters of hijinks ensue.
Don't look for a plot. There is one, but really, don't look for it too hard. Comedy.
Text: Light to Medium.
Furigana: YES!
Moyashimon (もやしもん)
Difficulty: **** for basic enjoyment, ***** if you want to get all of the biology references.
Description: Sawaki-kun can see microbes. They look like little cartoon characters, and this fact alone causes him all kinds of problems throughout his life, until he goes to college. Then it gets crazier. (Including childhood friend cross-dressing!) Lots of talk about fermentation. No, really a TON of talk about fermentation. Fun read even if you can't hack the vocab.
Text: Heavy. OMG Heavy sometimes.
Furigana: NO.
WitchCraftWorks (ウィッチクラフトワークス)
Difficulty: ***, sometimes ****
Description: Honoka-kun isn't very strong, tall, or smart, yet the tall, powerful witch Kagari takes an intense interest in him. Chaos ensues. (I love the artwork in this series. It's nuts.)
Text: Medium to Heavy.
Furigana: NO.
Minami-Ke (みなみーけ)
Difficulty: ***
Description: The 3 Minami sisters live alone: the oldest is a mom-like high schooler, the middle is the "mood maker"/troublemaker/instigator in middle school (boke), and the youngest is the smart, snarky kid in elementary school (tsukkomi). Lots of personality-based comedy. Tropes galore, but still well-written and amusing.
Text: Medium.
Furigana: NO.
Inari, Konkon, Koi Iroha (いなり、こんこん、恋いろは。)
Difficulty: ***
Description: Inari loves Tanbabashi-kun, so she makes a wish to Uka-sama, the local deity to look like her classmate, who she thinks is beautiful. A total mess ensues, as Inari winds up with part of Uka-sama's deity power, and becomes a deity herself. Sort of. But she's still not very good at love, relationships, or anything else. (Being a deity in this case doesn't make you any better than you were before!)
Text: Medium
Furigana: YES!
Kimi ni Todoke (君に届け)
Difficulty: ***
Description: Sawako is often mistaken for the horror movie Sadako, because of her long hair and reserved manner. She's just really shy. Watch her make friends and break out of her reclusive shell! It's shoujo-riffic!
Text: Light to Medium.
Furigana: YES!
Sora no Manimani (宙のまにまに)
Difficulty: *** for basic, ***** for astronomy terms/astrophysics.
Description: Ooyagi Saku returns to the place he lived from kindergarten until 2nd grade, and meets Akeno Mihoshi, his childhood friend from that time. She's really into astronomy, he likes to read books. Quietly. Mihoshi drags him into the Astronomy Club, and lots of astronomy, comedy, and some drama happens.
Text: Medium to Heavy (when explaining astronmy stuff.)
Furigana: NO!
Hayate X Blade (はやて×ブレード)
Difficulty: ****/***** (This is a tough read for me sometimes. She likes to use strange readings for kanji, seldom with furigana, and laced with obscure jokes. In spite of that, it's funny as hell sometimes.)
Description: At an all-girls school, there is a group of students who compete to be in charge by fighting in wooden sword battles. (The Hoshitori.) Lots of stupidity and hijinks ensue. It has serious-ish moments, but it's generally a comedy. Doesn't require a lot of thought. (Well, reading it can be challenging.)
Text: Heavy.
Furigana: NO.
GA 芸術科アートデザインクラス (Wrote out the title because otherwise you'll never find it.)
Difficulty: *** for basic, **** to get all of the art terms.
Description: 4-koma primarily about a group of 5 friends in the art dept. at a high school (with an attached college). Lots of art terminology, so it's good if you want to learn about art. Other groups get followed as well. Comedy. Nothing heavy at all. Some of the jokes are a little 4-koma-ish, so they may not always be that funny. Can get a bit bogged down if you try to look up everything.
Text: Heavy at times. (When Kyouju lectures about art, she can pound out the words.)
Furigana: NO. (Except the joke below.)
Note: totally ruined how I see 素描 (そびょう）. Now I always see it as 素猫 (す・ねこ！)
Hidamari Sketch (ひだまりスケッチ)
Difficulty: *** for basic, **** to get all of the art terms.
Description: 4 (later 6) art students live in the wacky Hidamari apartments while commuting to the school next door to study art. Some art, but mostly hijinks ensue. 4-koma, so 4-koma warnings apply.
Text: Medium.
Furigana: NO.
K-ON! (けいおん！)
Difficulty: ***
Description: I've seen promos for this book/show all over Japan. Especially Lawson. Anyway, a group of 4, later 5, HS girls form a band. 4-koma ensues. Comedy. Not a very difficult read for intermediate level.
Text: Medium.
Furigana: NO.
Golden Time (ゴールデンタイム)
Difficulty: ***
Description: Tada Banri lost all of his memories just as he was about to graduate from high school. One year later, on the way to his law school entrance ceremony, he meets Kaga Kouko, who is beating the guy he just met with a bouquet or roses. By the author of ToraDora! Manga version of the novels. (Great story, IMO.)
Text: Medium.
Furigana: YES! (If you read the books/manga, you may get this joke!)
Hayate no Gotoku (ハヤテのごとく！)
Difficulty: **, sometimes *** when it gets all "plotty," but that's not often. This was the first manga I bought in Japanese, and could muddle through it with basic skills. You can get by with * skill even, if you're patient.
Description: Ayasaki Hayate is sold to the yakuza by his parents to settle a 150M yen debt, then is saved by 13 year-old Sanzenin Nagi, who falls for him even though he tries to kidnap her (she misunderstands), then he becomes her butler, and 400+ chapters of hijinks ensue.
Don't look for a plot. There is one, but really, don't look for it too hard. Comedy.
Text: Light to Medium.
Furigana: YES!
Moyashimon (もやしもん)
Difficulty: **** for basic enjoyment, ***** if you want to get all of the biology references.
Description: Sawaki-kun can see microbes. They look like little cartoon characters, and this fact alone causes him all kinds of problems throughout his life, until he goes to college. Then it gets crazier. (Including childhood friend cross-dressing!) Lots of talk about fermentation. No, really a TON of talk about fermentation. Fun read even if you can't hack the vocab.
Text: Heavy. OMG Heavy sometimes.
Furigana: NO.
WitchCraftWorks (ウィッチクラフトワークス)
Difficulty: ***, sometimes ****
Description: Honoka-kun isn't very strong, tall, or smart, yet the tall, powerful witch Kagari takes an intense interest in him. Chaos ensues. (I love the artwork in this series. It's nuts.)
Text: Medium to Heavy.
Furigana: NO.
Minami-Ke (みなみーけ)
Difficulty: ***
Description: The 3 Minami sisters live alone: the oldest is a mom-like high schooler, the middle is the "mood maker"/troublemaker/instigator in middle school (boke), and the youngest is the smart, snarky kid in elementary school (tsukkomi). Lots of personality-based comedy. Tropes galore, but still well-written and amusing.
Text: Medium.
Furigana: NO.
Inari, Konkon, Koi Iroha (いなり、こんこん、恋いろは。)
Difficulty: ***
Description: Inari loves Tanbabashi-kun, so she makes a wish to Uka-sama, the local deity to look like her classmate, who she thinks is beautiful. A total mess ensues, as Inari winds up with part of Uka-sama's deity power, and becomes a deity herself. Sort of. But she's still not very good at love, relationships, or anything else. (Being a deity in this case doesn't make you any better than you were before!)
Text: Medium
Furigana: YES!
Kimi ni Todoke (君に届け)
Difficulty: ***
Description: Sawako is often mistaken for the horror movie Sadako, because of her long hair and reserved manner. She's just really shy. Watch her make friends and break out of her reclusive shell! It's shoujo-riffic!
Text: Light to Medium.
Furigana: YES!
Sora no Manimani (宙のまにまに)
Difficulty: *** for basic, ***** for astronomy terms/astrophysics.
Description: Ooyagi Saku returns to the place he lived from kindergarten until 2nd grade, and meets Akeno Mihoshi, his childhood friend from that time. She's really into astronomy, he likes to read books. Quietly. Mihoshi drags him into the Astronomy Club, and lots of astronomy, comedy, and some drama happens.
Text: Medium to Heavy (when explaining astronmy stuff.)
Furigana: NO!
Hayate X Blade (はやて×ブレード)
Difficulty: ****/***** (This is a tough read for me sometimes. She likes to use strange readings for kanji, seldom with furigana, and laced with obscure jokes. In spite of that, it's funny as hell sometimes.)
Description: At an all-girls school, there is a group of students who compete to be in charge by fighting in wooden sword battles. (The Hoshitori.) Lots of stupidity and hijinks ensue. It has serious-ish moments, but it's generally a comedy. Doesn't require a lot of thought. (Well, reading it can be challenging.)
Text: Heavy.
Furigana: NO.
GA 芸術科アートデザインクラス (Wrote out the title because otherwise you'll never find it.)
Difficulty: *** for basic, **** to get all of the art terms.
Description: 4-koma primarily about a group of 5 friends in the art dept. at a high school (with an attached college). Lots of art terminology, so it's good if you want to learn about art. Other groups get followed as well. Comedy. Nothing heavy at all. Some of the jokes are a little 4-koma-ish, so they may not always be that funny. Can get a bit bogged down if you try to look up everything.
Text: Heavy at times. (When Kyouju lectures about art, she can pound out the words.)
Furigana: NO. (Except the joke below.)
Note: totally ruined how I see 素描 (そびょう）. Now I always see it as 素猫 (す・ねこ！)
Hidamari Sketch (ひだまりスケッチ)
Difficulty: *** for basic, **** to get all of the art terms.
Description: 4 (later 6) art students live in the wacky Hidamari apartments while commuting to the school next door to study art. Some art, but mostly hijinks ensue. 4-koma, so 4-koma warnings apply.
Text: Medium.
Furigana: NO.
K-ON! (けいおん！)
Difficulty: ***
Description: I've seen promos for this book/show all over Japan. Especially Lawson. Anyway, a group of 4, later 5, HS girls form a band. 4-koma ensues. Comedy. Not a very difficult read for intermediate level.
Text: Medium.
Furigana: NO.