Top 10

On the forum I'm usually on were having this top 10 videogame list. I've been having a hard time trying to figure out whats gonna be on mine.
I feel like there are to many games that I have really enjoyed and that should be on the list.
If someone comes by this blog, would you be kind enough to let me in on what should define the top 10 games in your life.
 Was it the first really good game you played or the newest with the sickest graphics you've ever seen. 
Anyways I probably post the list when its complete.