Diverse game library, no hassle backward compatibility with the PS1 and the ability to play DVD movies right out of the box.

A great and diverse library coupled with backwards compatibility, a built in DVD player that was cheaper than stand alone DVD players at the time, and a great reputation it rightfully earned with PS1 led to PS2's success and "The Golden Age of Gaming."

Also doesn't hurt that the original X-Box was like 500 dollars when it first released and very few outside the western world would have anything to do with them, and Nintendo shot themselves in the foot with that Spaceworld/Celda fiasco. As for the Dreamcast, the gaming press loved to bash that thing every chance it got like a pinata or battered woman.

Little competition
Great Games
DVD Player

I'd say 3rd party exclusives/timed exclusives was pretty big factor too. A decent amount of big titles from 3rd parties were either only on PS2 and/or came out on PS2 first before they landed on another console: MGS2, MGS3, Final Fantasy's, Devil May Cry's, Grand Theft Auto, Tekken, etc... The PS2 was just the go to place for virtually everything when it came to software.

A lot of Japanese developers were just pouring out quality games back then on console too (many of which were only on PS2). The Japanese games industry was just booming back then.

Being the more affordable DVD player back then and PS2 being a game console to boot it's no brainer why it so successful.
Others weren't too bad either but PS2 sales were incredibly high and leave GC and
Xbox so far behind it made them looked bad.
Everybody should get more than one consoles from that generation,each one of them always have something worth getting for.
But PS2 got the most things right even though it's one of the weakest in spec no doubt it was so successful.
and the GAMES,you just can't go wrong with PS2 unless you have a crush on Mario
and master chief.
Playstation 2,the only console you'll never regret having two or more.
(My third PS2 coming this year)

Games.
Lots of games.
Lots of different kinds of games.
Lots of different kinds of games for different people.

Sony fully demonstrated that games sell hardware.

Those were the good days. Then the "hardcore" shooter fans were born and this war turned violent.

Dreamcast was not supported by 3rd party. Everyone made games for ps2. It was a DVD player.

Oh, and GTA3 really started the boost in ps2 sales. Killer App that no one else had.

Rather than make a long list (I dont do lists) of all the bullet points why PS2 was such an awesome console, tell me one good reason why it WOULDNT be successful?

There wouldnt be many.

It was honestly the DVD player. It had an amazing library of games but looking at how much each game sold compared to how many people bought the actual console speaks for itself.

I really wish Sony would duplicate the PS2 with PS4 and Nintendo duplicate the GameCube with the Wii U. Both had amazing games.

A huge factor was the DVD, it literally knocked the Dreamcast on it's a#$

A great library of games. Some of the best games were on the PS2. Not only that but most of the games were exclusive to the console and could not be played anywhere else.

It was coming off the equally successful original PS1.

I think one thing that really helped early on was you could watch DVD's on the PS2 and DVD players were still expensive. That was big back then. It wasn't as big for the PS3 and Blu-ray but the PS3 at least was cheaper than other Blu-ray players.

Over a year head start, DVD player, great 1st and 3rd party exclusives. Also, it was affordable for what it offered. Perk was PS1 BC. That was the last generation that offered so many unique A/B titles along with great AAA ones. I'll miss it..."tear"

i tottally agree with Concertoine!well said dude.i couldn't have said it better myself.

Rpg's

1) Dvd player out of the box! When the system launched dvd was still new and fairly expensive.

2) Exclusive 3rd party games! During the PS2 years Japanese 3rd party games were king and mostly found only on Sony's system.

3) Hardware and marketing! Because the PS2 was such a custom piece of silicon, everyone believed the hype of tech buzz words such as Emotion Engine and Graphic Synthesizer. Simply because during this time Sony was putting out very high end home electronics that were selling well, so the brand had much clout. (Not saying the brand doesn't have clout now, but PS4 wouldn't even need the Sony name to be a successful console at this time.)

Piracy

A heady mix of unilateral dev support, a dvd player, and a shit ton of hype.

Games and thousands of them
Built in DVD player
Bandwagon Effect
First console of it's generation and huge step up from PS1

The list is much bigger