For me it is second if you don't include portables.
1st. Gamecube
Though the game didn't get much support, the amount of ridiculously time consuming games was unriveled. I spent dozens if not hundreds of hours player super smash bros melee, Tales of Symphonia, Phantasy Star Online Episode 1 and 2, Mario Sunshine, Animal Crossing, Pikmen, Pikmen 2, Metroid Prime, Metroid Prime 2, Mario Kart Double Dash, Need for Speed Underground, Godzilla Destroy All Monsters Melee. Every gamecube game I ended up buying was just fun to play period. And I actually enjoyed the entire first party lineup.
2nd. Xbox 360
For those who down own a gaming PC, the only way to play Left 4 Dead, and the only console with playable versions of Bayonetta, The Orange Box, Elder Scrolls, and Fallout. It had a bunch of quircky new IPs near launch. I loved Viva Pinata, Kameo, Lost Oddessey, and Tales of Vesperia. The only "big" console exclusives that I really enjoyed on the console are Fable, Left 4 Dead, and Halo but boy did I love them. Then there are the countless of amazing multiplatform games that graced the system. Once I started getting into PC gaming, owning an xbox almost felt pointless, so I sold it. But for the 5 years I owned it, it was the most fun I've had with a console. Gamecube beats it simply because I still play on it to this day.
3rd Playstation One
(My first console. It could probably have been in first place had I got it when I was more educated in gaming when I first got it, but alas I was young, just moved to America, and only got what had appealing looking boxcovers. So while I absolutely fell in love with crash bandicoot, spyro, rayman, and croc games. I had to also suffer through scooby doo,power puff girls, and other licensed games.
