The X-Box is really your only option. The others are just plain trash, and that is everyones opinion.....

Sorry about the sarcasim, but really it is a personal preference! People will swear by one or the other. Its all about how you like your console. So your mission is to find out what type HE likes! For starters you might take him to a local best buy and sportingly offer him to a match on one of the consoles. This will not only offer a chance for conversation about it, but you'll be able to see how he likes it by his comments about it as you guys play.
Price wise they are all about the same with the gamecube coming in a little cheaper though it won't play DVD's.
The PS2 does have more games, but then the X-Box's list of games is growing nicely, and it looks to have a bright future ahead of it! Right now it has a large selection of awesome games out already though! The gamecube has a pretty good selection too about like the X-box in size, but a very different type.
As for the feel. The X-Boxs feels like a PC! It's a lot of fun that way! Infact it really is a PC! I like that in it! The PS2 is more the conventional console! It does all the conventional console titles, and has a great following of great console titles like grand torismo. The GameCube is a Zelda type thing. Most of the games seem to be aimed at RPG's. It's not as powerfull as the others so it can't do the amazing effects, but its still pretty nice. Any way, hope this helps some!