Gotta go with N64. I do own one but only have 5 games for it, 3 are racing games, one is a pool game and the other is Robotron 64 - the main reason I own it.
It's not that I think it's overrated now, I thought it was overrated when it came out. Super Mario 64 which was lauded as some gaming breakthrough seemed like a boring, childish mess with poor control and horrible cameras. I didn't get the appeal. Other than Goldeneye and Mario Kart which I owned BITD I thought the N64 was the poor mans PS1 and couldn't understand how anyone other than a 10 year old would want it.
Of course I was an adult and married with a child on the way when we first got it but when I had the depth of some PS1 and PC games to play, the N64 was a childs toy to me and if my wife wasn't so addicted to Mario Kart 64 we probably would have gotten rid of it much sooner. All my friends were also gaming on PS1 or PC's at the time I didn't know anyone other than myself and my young nephew who had one and even he preferred PC gaming.
Even in my current collection I've bought and sold the N64 many times because I get it and don't understand why but again, Robotron 64 is addictive enough for me to keep the console solely for it. Otherwise it's a console who's existence and popularity I don't understand. It was overrated then, it's overrated now. Long live the 2600 - still the best console EVER!