How Do You Measure the Value of a Video Game?

Some of us play games without worying about how much they cost. Others, like commenter Sol, want to make sure they're getting a fair amount of entertaiment for their money. How do you measure the value of a video game?

Is there any way you guys quantify whether you get your money's worth on a purchase? Or is it a gut feeling? I've heard people talk about the "dollar per hour" way of telling whether it's worth buying a game or not, but sometimes that just doesn't apply. At what point do you generally feel satisfied with your money? Were there any games you bought that made you feel cheated?

I tend to go with the dollar-per-hour for online games, but it's more of a gut feeling for single-player. If a game can't hold my interest online for very long I'll feel cheated, but if a five hour campaign just blew me away I won't regret spending my money. I felt cheated most when I bought games that I simply didn't like. Prototype was the only game I pre-ordered but didn't finish, and I wish I could get that $60 back. Otherwise I only buy if I'm pretty confident I'll play the game.
