For me was quite simple. Nintendo released a new console.

Already had a nice PC, so no need for the HD. Wii was something fresh, interesting, and, a few months after it's release, bound to be the console winner, so i've figured out that there will be 3rd party support, and that i won't be able to play wii games on my PC.

Perfect Dark Zero, actually. Which I ended up not liking anyway.

no I loved Fire Emblem.

it reminded me that I still enjoyed deep hardcore type games. I picked the PS3 MGS bundle with Oblivion and COD4. The Wii has some really great games for the core, but not enough. A core game need a Wii + HD console.

I would have "jumped in" eventually, but the Nintendo had me buy a console sooner than I thought I would. Generally I wait before going on to buying a next gen console. I think I'll go back to doing that next gen. That way I can see what each console has to offer, the consoles are cheaper, and so are the best games on each console.

PSP then DS then PS3 games.

Gears of War

Super Smash Bros Brawl. A bit late, I know, but that brings me to my next reason...

The Wii in stock. I'm sure if I tried I could have managed to find one earlier, but I was in no hurry... WoW made sure of that.

after a year or two with no gaming in my life all of a sudden my cousins boyfriend buys himself an xbox 360 and i was blown away/jealous at the same time..... i decided to "1-up" him and his nifty console so i went out a week later and bought myself a PS3 and have loved it ever since.... ;)

Zelda Twilight Princess, I wanted that game so bad...