I'm not going to rank these as the stand with me in 2012, but rather how they affected me during their generation.
1. SNES - The 16-bit generation was just an absolute blast for me, and the SNES was just such a kick ass system with strong games in every genre.
2. NES- Strong first party offerings for the time, and incredible third party support. Introduced me to Castlevania, Contra, Zelda, Ninja Gaiden, etc...
3. Wii- The Wii has what I feel to be the strongest overall first party offerings of any Nintendo system ever. Two solid Zelda titles, two strong Mario games, a beautiful Punchout return, excellent Kirby games, and Retro Studio's Metroid Prime 3 an DKCR, among other games. I've never enjoyed so many first party Nintendo games on one system before, but the system stumbles in third party content.
4. GBA- Introduced me to Advance Wars, Golden Sun, and some of the best Castlevania games I've played. Loved the sp model!
5. Gamecube - The Gamecube was my travel system, as we took it on vacations with us. Solid first party offerings, and easily the best launch of the last generation.
6. DS- I honestly never played much of the DS, but it did introduce me to Professor Layton, and had some good Castlevania titles, so that should count for something.
7. 3DS- Still too young and only a matter of time before this rises in the ranks for me. Especially with so many promising games releasing.
8. N64- Some very notable games like Super Mario 64, Zelda OoT, Goldeneye, and Starfox, but a few stong games here and there couldn't make up for such a shitty overall library.
9. Gameboy- For me this was the worst of the worst. Not a single one of my beloeved franchises translated into an enjoyable game on this hunk of shit. Sorry guys, but I did not like Gameboy.