Top five games I've played, huh? Let me think...
Valkyria Chronicles 2*
inFamous**
Monster Hunter Freedom Unite
Portal 2
Legend of Zelda: Ocarina of Time***
*I know most people would pick 1, but I felt that 2 overall had more to it, in terms of gameplay depth. Also nice was the fact that Shocktroopers were actually useful, because the maps were smaller.
**From the demo of inFamous 2, I got the impression that it was like inFamous 1 but better in most ways. Still, I haven't actually played it, so I could be wrong. Therefore, my vote for the first one stands.
***Oh, I came to gaming for Super Mario World, I stayed because of OOT.