Sonic: Generations.
I might be a bit biased since Sonic was my favorite hero back then. But hey, the game is nice. It is frustrating sometime, but it still has one essential element that every good games must have, it is "fun". One thing I don't like is how short the game is, I can just skip most of the challenges, beat the crap out of rivals, earn emeralds, and voila, last stage is where you are. Even so, it's still one game I do consider as way-above-average. It's full of nostalgia, it's fun, it's beautiful, it's high-speed, it's challenging, and the most important of all, it's Sonic.