Sega Master System: My bro loved Sega over Nintendo at the time.
SNES: Because my bro finally gave in to Nintendo.
Game Boy Pocket: Because all my friends had one.
Nintendo 64: Because at the time Nintendo Power Magazine was hyping it up as the next big thing and even sent a VHS tape of the games available to NP Subsribers. I was sold for a 10 year old boy. Never regretted getting it over a PSX
Gameboy Color: Because it's all you favorite Gameboy Games... IN COLOR!
Dreamcast: Because it had ALL THE FIGHTING games I love to play and lots of Capcom exclusives at the time. Plus Phantasy Star Online (The Mother of MMOs)
Nintendo Gamecube: Because I love everything Nintendo (even though I HATED the design and still do to this day). Don't also regret getting it over a PS2.
Gameboy Advance: A more advanced version of the Gameboy.
PSP: As much as I hated Sony, I didn't like the DS design at all (looked like those cheap chinese 10000 in 1 handheld game systems). Plus the games on it really looked great. And all my favorite Capcom games were on it.
Nintendo Wii: Not only do I buy everything Nintendo, the motion controls REALLY got to me. Was REALLY convinced this was the next big thing in gaming (boy did it loss steam fast).
Xbox 360: Because friend sold it at a great price and heard about how good CoD:MW was. Also because I couldn't stand anything Sony at the time. Enjoyed it after for a year then it RRODed on me. Sent it to Microsoft, fixed it(took a month to get it back) and RRoDed on me again a week later, sent it again and waited a month until...
...PS3: Bought it ONLY to be a Blu-Ray player (I was debating between a PS3 and a Blu-ray player, friends told me to go with the PS3 and I'm glad I listened to them). But when my X360 kept RRODing I got tired of senting it to Microsoft and just bought all my 36O games on the PS3 and problem solved (was like a Godsend to me!). 5 1/2 years later it still works! 
Nintendo 3DS: Bought it because I was wrong about the OG DS and it was backwards compatible. So wanted to play the remake of Pokémon Gold/Silver and the Zelda's I missed on. 2nd reason because of Fire Emblem games!
Nintendo Wii U: Although no games were available that were must have's at the time, I got it because of the Zelda Wind Waker design.
So yeah.
