I wouldn't say Sega's games were BAD, per se, but the BLY/WMS of the day were more loved by players and play a little more solid in my opinion.
A lot of people overlook South Park for a fun players game and the theme did well for earning on location and still does. It can be very repetitive though.
I just pulled up the list of Sega games on IPDB to refresh my memory and to be honest there isn't a lot that gets me excited. Maybe a good handful.