Ok, is this a "best console?" question, or a "what console do you own?" question? No doubt the PS2 will win the poll, because of its larger userbase.
For me, it has to be the Xbox. Ive owned all three, and also use a PC for gaming, so i feel im qualified to talk. Xbox live is the best way to play games online. Its miles better than the PC online games.
Also, Xbox is better graphically, and is the only console that can transmit true 5.1 surround sound. Ok, some games are now made in Dolby Pro Logic II these days, which really adds to a game. I think graphically, games are getting to the point where all developers can add is spit and polish. Sound design is the next big thing, particularly with the rise in popularity of home cinema encouraging decent surround tracks into games. Games like FPS and stealth games really need to be played in surround to get the most out of them. The Xbox does this better than any other. The Xbox has a hard drive, which i think should be essential for all consoles from now on in. You cant beat custom soundtracks in games, and the ability to download things.
I also think the Xbox has the best exclusive games. Nintendo made games are always going to be quality. PS2 games tend to be largely sequels of shit that we have all played to death (particularly the bollocks that EA continue to release!) or converted to all other formats, where the Xbox version (and Gamecube and PC versions) will be better. This is largely because Sony tried some experement with parallel processing, which really hasnt worked. The machine is a bitch to program for, and get the best out of. Despite this, Sony seem to be going with parallel processing for the PS3. Microsoft have decided to go with an uber-PC in a box. Which will be the best will be interesting to look out for.
The original Playstation was the best console of its era. Sony got everything right. Now they just cant be arsed, because they know that the average gamer will buy any old shite, therefore the PS2 has suffered. A shame.