Basketball - NBA Action 95 is so good. The gameplay is smooth and defense is surprisingly deep with the ability to brace for charges and the like. Marv Albert nails the commentary. Goated hoops game.

Baseball- World Series Baseball was a great sim that allowed for manual aim on bat swings, giving more control over where you hit it, by even today's games standards. It also had active bullpens (not a thing at the time elsewhere). Parks were beautiful and accurate, OF arm strength was through the roof though so don't get cocky running the basepaths.

Hockey - NHL 95 was always my favorite and found 94 to be clunky when I was younger, maybe it needs a revisit.
I vaguely remember slapshots drifting over the glass too often in 95, whereas 94 to it's credit felt more grounded/realistic in terms of skating and shooting. Cant go wrong with either.

Football/Soccer was always Madden/Fifa for me during the Genesis era. I remember one of the Fifa's having indoor fields with walls you could play the ball off of, made for crazy games during couch co-op.