ff7 had an anime ova.
don't put mainstream anime and suggest more mainstream anime, it doesn't work out.
Valkyria Chronicles was made into an anime.
hitman was made into a live action movie.
fate stay/night is an anime based on a game, that's done in the animeish style backdrop. and released another game after the anime came out.
mega man was made into an anime.
all of the final fantasy series are one shots except for the sequals such as x-2, xiii-2 durge of cerburus, etc. there's no typing them together. even if they could have during the early ff series. but as of current there's 2 ff series in action ps and nintendo. and lets not forget ff11 and ff14 which come to both pc and ps. they've done an 3d movie that was done totally american style and ruined the whole movie.
they've done many things like the marvel comics ova things. they've done devil may cry. as one example.
------------
there's a lot that should remain just as games.
and others have good anime potential. a lot of jrpg's are a gold mine for that sorta stuff. that's why when we think of the old school breath of fire, chrono trigger - they fit in perfectly. there's a lot of games that were never ported to america that we missed out on. either because the demand wasn't high enough or they never saw potential for the market. to be honest a lot of the games that weren't released for north america over the years should just be released on pc. i'm sure ppl can get controllers that mimic past systems. or even rewrite the controls for keyboard and mouse.
but anyway, back to games to anime - games i would want to see get turned into anime breath of fire is one of my favorites, back in the snes days before they tried to meld anime and 3d.
half-life, assasins creed, amnesia, gothic, neverwinter nights, or any real series that can go farther than 12 episodes.
on a side note, a lot of animes and movies get turned into games anyway.