My genesis collection, there has never been a better system

That 6 button joystick is a gem! For my money it's the best first party joystick released. The OG square Neo Geo joysticks come very, very close, but the trigger functions and heft of the Sega joystick give it the edge. You're not going to get a better joystick unless you're upgrading a third party joystick with commercial grade parts.

Someone else recommended getting Super SFII, which I second, but seeing as you've got the joystick, I'd suggest collecting the Neo Geo conversions on the system. Samurai Shodown is pretty good, and while the others certainly have their faults they're not without their charm and the box art on some of them (particularly the first Fatal Fury game) is fantastic. Eternal Champions is also worth picking up; I would argue that it's best played with a joystick and since few had one poor controls was a common gripe about the game.

I love the Genesis dearly, but the way that I see it pound for pound the Dreamcast is the best system ever made. The ratio of quality to crud in its catalog has all of the other systems beat by a considerable margin.

Personally, my all time ranking for Sega Consoles is Dreamcast>Genesis>Saturn>Master System (the graphics on some of the games on it are woefully underappreciated)>32X>Sega CD . It wouldn't be unfair to wedge the first Xbox into that list with a big fat asterisk between the Master System and the 32X as it was a bona fide Sega system complete with Sega games (Sega GT and Jet Set Radio) packed in with the system and several franchise games and some original IPs (if you haven't played Otogi, go out of your way to do so!) released exclusively on the Xbox.

/r/SEGAGENESIS Thread Link - i.redd.it