If my son was answering this he'd say Call Of Duty had brought him the most entertainment.
For me, it is John Noble who plays Dr. Walter Bishop in Fringe. The series itself is so refreshingly different but Walter is definitely the star of the show. The way he portrays his character, quirkily detracted and distracted from the reality that surrounds him but yet so in tune with what needs to be done, his idiosyncrasies such as just suddenly blurting out what he fancies to eat even at the most inappropriate moments are pure genius. Sometimes I just don't know whether to laugh or feel sorry for him.
I'm so impressed with him that I bought both my parents and my OH's parents the DVD boxset for Christmas. If I had it my way that's what everyone would have got, it's a real must see.