I like several of the listed consoles there... particularly Master System, SNES, Genesis/Mega Drive, Saturn, & PlayStation (I've never really played the other ones very much or at all), but I have voted for the good 'ol Mega Drive since it was the first true console I ever played on and which introduced me properly to the whole console gaming world.
I still remember buying it with my family from the first Future Entertainment Show in Earl's Court back in the end of '92 - although it was a Christmas present so it's not like I immediately took it out of the box when we got home.
One of the first games I ever played on our then brand-spanking new Mega Drive was Sonic 2, although I also got Sonic 1 around the same time as well, I think it came with the machine.
I also love the Saturn for some of its great games and music, in particular NiGHTS and its Xmas sibling, Christmas NiGHTS.
Utter beautiful classics if you ask me - the series should return ASAP, and it should be as good as the original Saturn offerings.
Shame this isn't a multiple-vote poll similar to DPainter's New Year's one...