I agree with Zifei, Shingeki no Kyojin is amazing, and the plot twist that shall come to the anime soon.. Will be great

I'm a sucker for action/adventure/fantasy, I have seen many hundreds of anime shows, some are definitely better than others.. Off the top of my head a few I recommend...
Hunter x Hunter 2011 -Loved the original, 2011 gets through the original a bit faster, then continues passed it, can't wait for next episode every week...
Suisei No Gargantia -awesome new show! minor mecha theme but Love it so far.
Sword Art Online -Similar to .hack//sign.. I thoroughly enjoyed it!
D.Gray-Man -Action.. Adventure.. Demons.. Hell yeah?
One Piece -Another Action/Adventure/Fantasy, love how they explore tons of interesting places
Toriko -Same as above, but makes me a bit hungry every time I watch a new episode...
Btooom! -Had pretty interesting horror theme to it. Was an interesting show to watch, though I probably won't watch it again.