1st Recommendation: Resistance 2
Better in every way? Hell yes. This is one of the most feature packed first person shooters around. Between the campaign, co-op and competitive mode, you'll be spending months playing it all.
The only complaint? Apart from some small issues, the game also plays differently to the original. It now feels more like Call of Duty 4 instead of the first game, which had a unique feel. You can always pick up the first game at a budget price.
2nd Recommendation: LittleBigPlanet
The idea was sound, but whether Media Molecule could pull it off was a different matter. And they did. LittleBigPlanet is a great game, the graphics, physics and of course Sackboy all come together to provide a unique experience. It's a platformer, but it's also highly challenging and fun to play for all ages. After completing the game, you can create your own levels with the very complex level editor. There's also four player online co-op for both the story and user created levels!
3rd Recommendation: Motorstorm: Pacific Rift
Better in every way compared to the original Motorstorm, you can't go past Motorstorm: Pacific Rift for your racing needs. Now Motorstorm was a great game, but it was a very frustrating experience and many people gave up playing due to the obtuse learning curve and challenging AI.
The improvements in Pacific Rift are plenty. Stunning graphics, better handling, AI, physics, faster loading times and new inclusions such as 4 player splitscreen and trophies. And the graphics? Yeah, they're phenomenal.
The sequel is still quite challenging, but it's much more rewarding and fun this time around. Don't judge the game on the demo available on PSN, it's actually one of the worst tracks in the game. Motorstorm: Pacific Rift is definitely one of the best racing games this generation and probably the best off-road racing game ever.