Just opened my Twitter and got a follower whom having a sheet music forum. I did a mini research and these are other big sites that may useful for you. Note that comparing to the first article, the websites I listed below have limitation in quantity. But still, they are worth it to see:
ShareMusic.com : the title might make you think it's a pay download file but nope! Not at all. It is obvious that the site will potentially grow bigger. The collection is actually varied from Western movies to Anime. You can find Legend of Zelda's transcription here.
L'indestin : the copyright showed me it was made from 2004. I don't know whether this site is always updated because there's no date of update file. However, the collection is interesting. It includes Byousoku 5cm which - in my opinion - is quite challenging to play.
Sebastian Wolff : it doesn't have too much of anime/game sheet music but the good thing is.. it refers you the websites that provide it. Another interesting matter : it has tutorials for piano like how to play as accompaniment and improvisation techniques.
Piano Squall : you also have to consider this site, especially if you're a Final Fantasy and Tetris fan. The site itself is unique. I think this is the first time I see an anime/game sheet music website that also refers for charity.
ps: for the first article, click here