Genesis. Not too bad considering the other alternatives lol. Would have liked a more modern console though :P

Trade anyone for a BC compatible PS3.

Nope, I dn't want to play neogeo for the rest of my life.

Nintendo 64. Sweet.

PlayStation for me. I have a good library of games for the system already, but last time I went back to play one, they have not aged well and are very rough on the eyes. One of the reasons the PS Classic did so poorly (combined with Sony putting in zero effort in the unit as it was).

N64, least I can play OoT

I'm stuck with Atari 2600. At least I didn't get the Leapfrog, whatever the hell that thing is. I think I'd rather throw the Atari in a fire and dance around it a few times chanting satanic verses than play the damn thing.

I got the Switch! Sweet! Especially since I managed to nab one of those Mario Kart Live Home Circuits. Way too much fun was had this weekend.

PS1.
dated but large & varied library... I guess i'll take it.

Given this is about "only game system for the rest of your life" do we have to take into account durability? I mean in terms of games I would prefer a modern console, but with many of them you are lucky to get 5 years of extensive use out of them... The Gamecube is probably the only disc based console that might last a lifetime (although the PS1 often had fixable quirks, a friend of mine had an old one that only worked if you turned it upside down, and I think the PS2 slim version is pretty reliable)

In simple terms, it's a portable Sega Master System. It has the same internal hardware and thus could actually play Master System games with an adaptor.

And yes, it did consume a lot more batteries than the Gameboy, and that's why it mostly failed. However, they were not nearly as bad as many would make you believe. They just used the cheapest batteries which didn't get high enough Ampere for the system and thus had zero battery life with those suckers, but if you took some better batteries it did last for up to 6-8 hours, with most alkaline batteries of the time giving you 5-6 hours of battery life. Problem is, the Gameboy lasted 10-16 hours with less batteries, and it could use the low quality made in China Carbon-Zink batteries that the Game Gear refused just fine, so this looked pretty bad by comparison. Also, now there exist battery mods for the Game Gear which give the system a rechargeable Li-Ion battery strong enough to make it last almost half a day nonstop.

https://www.youtube.com/watch?v=Tpfvy_iZxCc

It lasted 7h32 with coppertop batteries like the ones you could buy when the Game Gear was fresh out.

Also, the games on it are actually quite good for the most part, and with the Master System adaptor, you'd actually have a great game library. So not the worst pick by far I'd say