So I've done pretty much all of RTK(although I stopped doing reviews for it because I got way to bored of it), and I'm currently working through core 2k and 6k. I'm only on step 5 of core 2k. That combined with all the words I've looked up while reading and playing games I probably know about 1500 words or so. So not very much.

The way I do Core 2k/6k is I have 3 facts for each vocab word. I have the word in Kanji on the front. I have the sentence in Kana/Kanji on the front, and the listening on the back. And I have the listening on the front and the sentence in Kana/Kanji on the back. When the Listen cards come up I make it a point to write out the sentence before I show it. So I think that gives me a fairly adequate amount of writing practice, although it does slow down the process of acquiring new words by quite a lot.

I'm getting pretty close to done with Japanese the Manga Way as well. I was wondering if what else I should pick up to go side by side with core 2k/6k. I've heard good things about the Genki books, I don't really know how useful they are and if they are interesting or not.

I'm mainly just looking for something else to do besides Core 2k and 6k. I play a lot of games and read manga in Japanese, and besides the occasional game in english I can't pass up (portal 2 for example) I get most my entertainment from Japanese.

Through games/manga and core 2k I feel like I get a pretty good amount of exposure to new vocab words and listening/writing/reading practice. And I don't really plan on working on speaking till I'm more confident that I can convey ideas somewhat coherently. But it seems to me that besides Japanese the Manga Way I haven't gotten very much in terms of grammar study. So I'm not sure if that's what I should be looking for after I finish Japanese the Manga Way.

Any input is appreciated. =)

JSPEC (Japanese Sentence Patterns for Effective Communication)

JLPT Grammar Books (you don't have to actually take the test. just use it to learn grammar)

Watch Japanese TV dramas with Japanese subtitles (and use SRS if you feel like it)

The answer to 'what do I do next' is always:

Find something you enjoy and start doing it.

If you have no idea what to do next, it's a sign that you're ready to find out what your weaknesses are. The only way to do that is to start doing something you want until that weakness appears. (If it never appears, the answer is "You're at your goal! おめでとございます！")

If you start reading and find you don't have enough vocab, find a vocab book that's slightly too hard and start in on it. (Or site, or whatever.

If you start talking to someone and find you can't understand them, some listening practice is in order.

Etc, etc.

Japanese isn't about studying. It's about your goal.