With over 160 million units sold, it's the undisputed king of consoles.
Of course, sales don't always translate to quality (as anyone in the entertainment world understands), so the question is simple: Is the PlayStation 2 the ultimate console overall, in terms of quality and sales?
It's an interesting question. The PS2 was like the perfect storm; Nintendo was suddenly facing a stiff competitor in Sony after the original PlayStation hit hard, Microsoft was just starting in the console game (pun intended), and the Dreamcast fizzled. The PS2 outsold the Dreamcast, Xbox and GameCube combined…several times over. That wasn't a race; it was complete and utter domination from start to finish, and we'll never see that again. The industry has changed radically since.
Did the PS2 deserve this lofty status? Well, maybe it did. It had the widest variety of genres (by a long shot), it pushed the boundaries of interactive entertainment almost on a yearly basis, and it had a lot more games available. In the first year alone, the PS2 produced some of the finest titles in the history of the industry: Grand Theft Auto III , Metal Gear Solid 2: Sons of Liberty , Final Fantasy X , Soul Reaver 2 , Red Faction , Gran Turismo 3: A-Spec , Twisted Metal: Black , Onimusha: Warlords , Devil May Cry and many more. And that was just the beginning.
If you look at a list of the top video games of all time, many of the titles were on the PS2. That should say something. Let's also not forget that it was the first console to offer a DVD player and full backwards compatibility, thereby increasing its appeal right out of the gate. All things considered, I'd say yeah, the PS2 is the greatest…and the sales reflect that.