40+

How can you possibly have too much entertainment? Generally, I'm happy with an RPG that is 20-25+ and a FPS that is 15+ (since they tend to be over faster). That said, the most play time I get is from strategy games like the TW and Civ series. With various difficulty levels and (in Civ) random maps, they have almost infinite replayability. I played Crysis and enjoyed it, but I'm done. By contrast, I've been playing Civ IV for two years and I'm sure I'll be playing it for at least another two years. There's no doubt which title wins on value for money.