I used to be a SEGA boy when I was younger, but after the terrible Saturn and Dreamcast and SEGA's eventual withdrawl from the console market I switched to the N64, which was my first console with Nintendo. I loved it - mainly for GoldenEye and Perfect Dark, but it was the most addictively playable console that I had owned and probably will ever own.
I bought a 2nd hand PS1 not long after and was hooked on WWF, Gran Turismo, and Grand Theft Auto, and have subsequently owned all of the PS family (including a number of PS2's - 4 I think!) even though I'm embarassed to admit that I rarely use my PS3.
My missus bought a Wii about a year ago, so we play on that together and with mates, but she isn't really into gaming - especially on the PS3.
I haven't had much experience of the XBox, except with playing Halo with some mates after the original XBox was first released, and I just didn't like the controllers at all. I played on a demo 360 in a shop when they were first released, and if anything I found the controls had gotten worse!
If I had to pick one of the three main consoles on the market at the moment I would pick the PS3 in an instant - with it's Blu-Ray capabilities and free online it's a sensible choice. The Wii is fun, but most of it's appeal is about gimmicks which wear off the more you use it. Plus even though the console is cheap, once you've bought all the attachments and add-on's you need to make it more 'fun' it's about the same price as a PS3. Also, the games available on Wii that are available on the other consoles have had content removed to make them 'simpler' to accommodate for motion detection gameplay, which is okay for the simple, less in depth games, but anything more serious like Resident Evil - you're definitely better of with an XBox or PS3 if you're after content rather than gimmicks.