SNES/SFC. I was the biggest ninty fan back then, to the point where I would have arguments defending the system. (I've since changed after from shitty customer service from them as well as their consoles not aligning with my playstyle).
But man, if you thought the SNES library was big, add all the JP exclusives. And "region lock" was just matter of getting a $10 adapter to make the cartridge fit. Many of the games stand up today.
Looking back I think it's neat to see how marketing affected our perception. "Sega has the best sports games & the fastest processor" was one I heard all the time. But 'blast processing" was just a programming technique, not hardware, and SNES games could go just as fast. Roadrunner's Death Valley Rally (Yes, the bird running away from Wylie Coyote) was easily just as fast as any sonic game, and it was one of the earlier games! I always found it funny that the sega ad made fun of Mariokart, but off all the games in the ad, it's the only series that's still going strong.
There were plenty of good sports games on the SNES too; NHLPA was pretty awesome, and both NCAA Basketball and NHL Hockey gave us a taste of the 3D sports games we see today.
That said, Megadrive wasn't that behind. "SNES has better graphics" may have been true at the beginning, but programmers found ways around that. Remember how Street Fighter 2 for Megadrive looked HORRIBLE compared to the SNES? Then they somehow made the Turbo edition look on par with the SNES. Makes you wonder what programming magic they used. And processing power is all about how you use it: Aladdin for MegaDrive was universally considered better than the capcom SNES game, so much so that re-lease on the switch is including the virgin game and skipping the SNES game.
I think I didn't like how the Sega ads always made fun of the SNES. As kids we were taught to take the high road and I guess that spilled into games as well for me. But looking back, I'm glad sega had a strong following since now there's a market to play their games from back then, and it all feels new to me.