I never really switched other than maybe what I would start with, long story short:
-Mario 64 convinced me to buy a n64 over first
-halo convinced me to buy a Xbox over a ps2 first
-PS3 sucked so bad when it came out, it made it easy to buy a much cheaper and better supported x360 at the time.
-MS E3 conference debacle in combination with the benefits of PS+ I get from Sony made the PS4 a easy first choice, plus no halo yet or for a good while. Plus Naughty Dog is HOTT with game badassness making great games for Sony.

*scratches head*  *smiles*

it's kinda like that.  I felt like such a skank!

SEGA stopped making them. I had no choice but to switch.

I got a PS2 for a surprise Christmas gift one year and played a few games for it (a couple exclusives and the rest multi-plat), but didn't fall in love with it. Then my friends all got Xbox and Halo, and once I started playing it I was blown away. I wound up buying my own Xbox for Halo/Halo 2/Fable, and I've been an Xbox fan ever since. I have always found Xbox exclusives to be more appealing on the whole than Sony's offerings.

Went from a PS2 to an Xbox 360, main reason was because I wanted to play Halo 3 with all my friends. I did end up buying a PS3 a couple years later though, and my choice for this gen was a PS4.

I went from Sega Genesis - PlayStation - PlayStation 2 - PlayStation 3 - PlayStation 4. For every console except for the PS4, it wasn't really my decision. My parents had a Genesis when I was born, my nana (grandma) bought a PS1 for me and my brother, and my step dad bought a PS2 and PS3.

EDIT: I have to say that the Wii was my main console for 2008, I guess I was caught in the Wii hype. I eventually went back to the PS3.

I own all systems, but my main console of choice has been:
PS1-> N64 (for 2 games)-> Gamecube-> Wii-> 360-> One (shall be my main console of choice this gen based on total 3rd party support, and controller preference). I also like achievements :D

Had a ps1 then ps2 then a wii then a 360 to a ps3 and finally both the ps4/xb1 plus a mid-high end gaming pc.

I only changed from ps2 to the wii60 because it was what everyone had and I was young so didn't know better. PS3 I got in 2010 made me realize my passion for gaming, ps1 nostalgia and Crash Bandicoot turned me into a Sony/PS fanboy ever since. I only got the xb1 because it was super cheap on ebay when i bought it and I really want to play sunset overdrive. I'm also more of a fan of Sony's first party and the variety of genres they offer with their exclusives. Sony's vision is on par with mine when it comes to gaming and that's why I favor them more than MS. Nintendo and Pokemon will forever be in my heart too.

It's strange, my friends seem to switch a lot. Here's some of my friends:
Friend #1:
1.Nintendo 64
2. Sega Dreamcast
3. XBox
4. XBox 360
5. PlayStation 3
6. PlayStation 4

Friend 2:
1. N64
2. Nintendo GameCube
3. Wii

Friend 3:
1. Nintendo 64
2. Nintendo GameCube
3. PlayStation 2
4. PlayStation 3

Friend 4:
1. XBox
2. PlayStation 2
3. PlayStation 3
4. XBox 360

Friend 5:
1. XBox
2. XBox 360

Friend 6:
1.Nintendo 64
2. PlayStation 2
3. XBox 360

Cousin 1:
1. PlayStation
2. Nintendo GameCube
3. PlayStation 3

I think you get the point. They seem to switch a lot.

I seem to switch every generation. (And for the sake of the conversation I'm just going to leave out Nintendo, for which I have a separate allegiance.) This was how I saw each console early in each generation:

PS2 was awesome, Xbox was just for dudes who wanted to play Halo.
Sony was making great games, and Microsoft was just trying to be flashy and douchely edge their way into the market.
I rooted for Sony.

PS3 was for techie turds who would sacrifice everything for a bit more power, Xbox 360 was awesome.
Sony was the petty, power-hungry company without a shred of originality, and Microsoft was making great games.
I rooted for Microsoft.

PS4 is awesome, Xbone is a bloated, commercialized piece of filth exclusively for COD dudebros that can't make a decision for themselves.
Sony is empowering gamers, focusing on making great games above all else, Microsoft is treating their customers like nothing more than pathetic blips on a sales report and insisting that we don't know what we want.
I'm rooting for Sony.


Who knows how things will turn out down the line?

It seems like a lot of people switched from Dreamcast to XBox. I had a friend who did that too.