Daytona USA on Saturn and Dreamcast.
Sega Rally (Saturn) and Sega Rally 2 (Dreamcast).
Played Virtua Tennis 2 on Dreamcast, couldnt beat computer on hardest level, on PS2 its not that difficult.
I tried Dreamcast Power Stone, I suck so much in 3D beatemups, platformers and Tomb Raider clones, had no chance in this one
edit - tried Sydney 2000 (DC), I like this kind of games but this one sucks. Average, boring, just like Int. Track and Field. Best summer olympics/decathlon/track and field games are Athlete Kings for Saturn, Track & Field and Hypersports (MAME) imo.