Here's a pretty good list of games that are either enhanced by using Sixaxis controls or just good if they are mandatory.
- Flower (general controls)
- Heavenly Sword (loved controlling projectiles. It sucked the first time you try it, but now it's one of the few reasons I would recommend anyone to play it)
- PixelJunk Eden (the whole shoot-to-the-ground thing works well)
- Uncharted/Uncharted 2 (the lean back thing)
- Heavy Rain (immersion)
- Army of Two (reload and parachute controls, believe it or not)
- Ratchet & Clank Future: Tools of Destruction (hated the flying, but all the other minigames were pretty fun)
- Killzone 2 (the sniping was very well done!)
Then there were implementations that were good/fun, but didn't really enhance anything.
- Metal Gear Solid 4 (changing the camo suit back to default and shaking boobs)
- LittleBigPlanet (looking around and hip-control)
- Ninja Gaiden Sigma 2 (more boob control, embarrasing but funny 
)
And then there is a long list where it didn't do any good. But I can't be bothered to write that down
There are probably more games out there, but these are pretty much just off the top of my head. And Dead Space and RE5 should have had Sixaxis controls for shaking creatures off, instead of raping your controller to do it!
