I was a Sega kid and definitely would have gotten a Saturn for that price. Sadly, the only place that stocked Saturns at the time was 57 miles away from me and my parents did not want to make a two-hour round trip just for me to get a few games. I remain convinced that the surprise launch in Summer 1995 is what truly killed the Saturn, because even kids like me that wanted one couldn't get one. Only Toys R' Us, Babbages and other specialty stores carried them. Wal-Mart, Target, Bestbuy, Circuit City, etc. didn't carry it. 

The release of the playstation was one of the best things to happen to the industry.
Selling record many units as the newcomer, pulling long time developers for other systems into making games for the playstation and putting a knife in the side of Nintendos pride and stubbornness.
Even making games kind of cool in the process.

Playstation 2 was of course a gigantic success as well. But I think it more so rode on the road paved by the PS1.

PS1 - the "we're new to this market, but we're smacking left and right and taking names" console.

I'd say the PS1. It broke Nintendo's dominance of the console market. It drew the support of most of the big Japanese third parties, some of which made few if any games for the N64. It proved that discs were the future format for home console games (carts only persisted afterward on handhelds). And it was the first console to make a huge breakthrough in Europe, which propelled it to over 100M units sold, something no other console had done at that point since in the 8-bit & 16-bit eras North American & Japan were the only big markets for consoles.

The PS2 was the bigger console sales-wise (even if you ignore the long tail post-PS3), but it mostly just carried the momentum Sony had from from the PS1 and built upon it, to the point where no other system really stood much of a chance of facing it in even terms.