I was a long time user of Sony PS1 and I own a PS2 (just about to try and flog it off with all it's games etc).
I used to think the PS1 was an amazing piece of gear. At the time, there was nothing that could touch it (Those were the days when Wipeout and Destrcution Derby ruled). When I bought my PS2, the promises of network use and built in hard drive etc. took ages to appear. When they did, they were less than inspiring and expensive here in Aus. I still enjoyed using my PS2 purely as a games platform. I briefly played with it as a DVD player, but it's inability to play multi-region (without hacks - and I buy quite a few DVDs from overseas), and it's extremely noisy fan stopped that pretty quickly.
When I bought my PS2, I don't think the XBox was out, but when Xbox came along, I thought "there's no way people will go for it over the PS2. The PS2 is way sexier". And, IMO, it is a slicker looking piece of gear. However, about six months ago, I decided to grab an xbox (they are really cheap now), and modify it (new case, modchip, 250Gb hard drive etc), and I now believe it's a far superior machine to the PS2.
Now the Xbox 360 is out, and PS3 is just around the corner (here in Aus anyways), and I find myself thinking that the xbox 360 is a far slicker design than the PS3. MS have taken a leaf out of the ipod design book, while the PS3 looks like a PS2 inside a hamburger bun. Sony are just trying to introduce their gaming network now, while xbox-live has been around for a while now.
I used to say to people "Ya know, I'd never buy any piece of Sony gear, apart from my playstation". Now I'd say "Ya know, I'd never buy any piece of Sony gear". I hate they way they try to force people to use their tech, even if it's not as smart a design as others on the market. I used to think they were cutting edge, now I just think they're cutting the cheese...