I have a bad tendency to keep going with any game I get started with.
On the other hand, for most games you can't really say within an hour if they're really good or bad.
For example this LotR game is pretty good for the first hour, but after leaving Shire it's like a completely different game - one made by few people with no interest on the job and zero budget.
I tend to give up on any game in about 1/2 an hour. I have been playing Asphalt for about 3 days now. Only about 15 minutes a session. I'm having fun crashing and the graphics are pretty good. I like the music.