Yeah,
Dragon Knight Saga is the best!
Dark Souls is supposedly great. I have it lying around, but I haven' gotten round to it yet.
I haven't actually played 'classic' RPGs like Divinity on XBOX as yet, but there are a few action-with-light-RPG-elements games I thoroughly enjoyed.
Enslaved for instance is a blast and takes you on a journey through a post-apocalyptic world that is not bland and drab for a change. Especially the first levels that take place in a human-free, overgrown New York City rife with autumn colours are a feast for the eyes.
Hunted: The Demon's Forge I can definitely recommend too. The reviews for this game were mixed, but I don't really see why. The characters are great, the combat is fun, there's lots of (big!) optional areas with puzzles and it's well worth playing the game at least twice because you can play with either a melee fighter or an archer, each with his/her own skills. Good stuff.
My favourite XBOX game so far has been
Castlevania: Lords of Shadow. Talk about an epic game. It's so big it comes on two discs filled with absolutely wonderful areas to explore. The graphics are the best I've ever seen on the platform, period, and the game is the ultimate mix of challenging combat mixed with clever puzzles and level exploration. Every location you travel to is more beautiful than the last and after finishing the game you really feel you've been taken on a voyage like no other. Be warned though that this is a difficult game that you'll have to learn how to master. Be prepared to die a lot in the beginning. (Same goes for Dark Souls I hear.) Once you get the hang of the combat though, you'll see it's actually fun to go back and try your luck on a higher – or even the highest – difficulty. You really have to see this game to believe it. The artwork is just stunning and because of the fixed camera angle, every shot is carefully chosen, resulting in spectacular imagery. Yeah, this game makes me go all lyrical. And did I tell you the narration is done by Patrick Steward? That's right! Not to mention it's dirt cheap by now.