There are many games that could be adapted into films and some even have the blue print layed out.
God of War - Could take some tips from Clash of the Titans, Wrath of the Titans and 300.
Uncharted - Could take some tips from Indiana Jones and Tomb Raider.
Heavy Rain - Pretty much a film in itself though can take some ideas from the movie Kidnap
Jade Cocoon - This could work well into a story if they can get the creatures right.
Dynasty Warriors - I know Dynasty Warriors is based off Romance of the three Kingdoms novel, and that there are many Movies, TV series, Cartoons and Animes based on the Three kingdoms era. But I would like to see something based off Dynasty Warriors the game where the characters have the same models from the games with the unique weapons, armour, horse, fighting style, stages and elements rather than your generic sword, spear and bow like it originally was in that era.
I also think Metal Gear Solid and Devil May Cry could be great if executed properly but Im sure these 2 will get done in the future given their popularity.