I found the old Trump "F2P shaman" upgraded with some GvG and Naxx cards did decently well to rank 13. I used Loatheb (legendary from 2nd Naxx wing), Sludge Belchers, Annoy-o-Tron in place of Feral Spirits, Nerubian Eggs. But then I got frustrated against Handlocks, playing long games and then losing to Dr Boom, Rag etc when I run out of Silence and Hexes (basically if handlock has a good draw it's very hard to beat with F2P Shaman I feel).
So then I tried again the old F2P Warrior from Reynad which I find really fun to play. These are the
GvG / Naxx replacements I made, v1 and v2. This is still a budget deck, it's supposed to have 2x Frothing Berserkers (rares), and Gorehowl instead of Arcanite. The idea with Piloted Shredder is to not lose too much tempo by having minions stick on the board, that said I'm trying different 3 and 4 drops. The silence is instrumental and won me several games, esp . against Druid. I can't even craft a second one! :p But I think I would go for a second one. They are 4 attack which is good vs Priest, and you still have a decent minion on the board. Yesterday I started experimenting with the 2x Slam. The idea is that it could help remove a taunt, and cycle a card so you don't lose too much momentum, and it can remove early minions. Loatheb won me games too so basically that's the only legendary I have that seems to work here.
I kept track of wins/losses and it was doing 2:1 on a good day, and a little under 1:1 against lots of hunters, but that was before yersterday's nerf to Undertaker. Pretty funny yesterday saw quite a few people still playing Undertaker on turn 1 or 2
I think that deck has potential to climb more, if you can afford Gorehowl, Frothing Berserkers, ... i'm contemplating doing another 2 Naxx wings to get Deathbite... I might not see Gorehowl in a long while. I'm not sure what are my cheapest options to improve the overall value of the deck atm, I am curious to see how the Slam's will do as I just started them yesterday.
Yeah Shredders are fun

Lorewalker Cho is probably the most annoying I've seen out of 2 drops, giving your spells to the opponent, and not being able to remove it from your board.
In a couple days all the legend players are going to climb again... oh dear.
ps: and yes the game is better in moderation, since I re-installed for the third time (cough) I made a point to stop playing whenever I become angry/reactive, and at least a couple hours before bed.