24" is a nice size for gaming, i use a 27" and would have even bigger if funds alowed
Are you "upgrading" from 16:10 to 16:9? I ask because a 16:9 24" is exactly the same height and simply gives a bit more width.
http://www.displaywars.com/24-inch-16x9-vs-22-inch-16x10
Too small if anything. I'm 23" and sit about 2' away.