I'm a Total console gamer. Been one for a while, my hobby is games, and the news behind them. I own a GCN. I could only get one console so went for it. Your not going to find Nintendo's games anywhere else and they already have one of two worth the console purchase alone. So my take on it.
The PS2: Games, games and more games. You'll find some really worth wild ones, and bags on top of bags of really bad ones. The graphics on these game are of course the weakest and load times are also the longest. But the PS2 is also the most supported ANYWHERE. Online, ebay, stores to your grandpa 's garage. And has a fully working DVD right inside. Down side, it's the worse power pushing console out there. No HDTV support or decent Surround Sound Support. Also it's one of the worse built. Some people buy up to 3 PS2s because on how they break, with help or on their own. Sony is even criticized by Capcom for making them so cheap they are meant to break. Now for this system, you need Memory cards that cost about $30 each. They are required. The controller is well, simple. You shouldn't have any trouble understanding it. Oh and it has online gaming, dome games are even free.
Xbox: The best Power pushing console there is. 20% more powerful then a GCN. So Xbox only games and multi-console games shine on this system. It is also the console with the most features, the best accessories support (HDTV, Theater Sound LAN gaming). Microsoft also goes a good way to get some super games for the system. Sadly though, their strongest line up ever has been nothing but delays. Some are even risking to be next gen games. Then you have Xbox Live, sounds good on paper, and for the most part is. But like playing in a public gaming store, there are people just out to fool around and will be a pain to play with. It's also BB only and cost $50 a month. Really good deal. Now this baby has a HD so no cards are needed. And the controller, is well, depends on the person. Some like it others don't. The big picture here is, if you get a Xbox, you just feeding fuel for Microsoft's dream of talking over your living room.
Gamecube: This be the system I own. It's the middle console as they say, often way over looked and underrated. And for it's own reasons. First though, this is the only console you'll find Nintendo games. That goes form Mario to Metroid to Zelda ect. it's needs cards but they are the cheapest in term of price out there and the console is very well built with the lest amount of problems. The controller is has a really good glove design to it. Down side is some button lay outs and the fact it has the less amount of buttons. GCN games also cost the most because of the disk formate but have decent to Xbox quailty graphics with the fastest load times. Some bad promoting for the console though has slip it from some stores. So finding good prices on it's games isn't always easy. Speking of the games, you have issue 2 with the GCN, the kiddy image and that's Nintendo's own fault. There are games that will up front seem to kiddy for your taste and there is not a lot of mature titles on the console. Plus no online gaming.