Carrier and a lot of the other games listed here are MASTERPIECES compared to some Dreamcast games, I think a pretty accurate list of the worst games (from my own experience) would be:
18 Wheeler
Ducati Racing
Evolution
Fighting Force 2
Giga Wing 2
Godzilla Generations
Godzilla Generations: Maximum Impact
Heavy Metal: FAKK 2
Maken X
Omikron: The Nomad Soul
Plasma Sword
Re-Volt
Spawn: In the Demon's Hand
Soul Fighter
Time Stalkers
Toy Racer
Everything else IMO is pretty good if you're into the specific genre that game comes from.
D2 was more of a disappointment than a disaster, because there's a LOT it does right, yet so many minor things missing from it and it's rediculously easy (another game where you have to actually go out of your way to get killed). Unlike most games of its ilk though I thought it was brilliant that you actually START the game with a sniper rifle and a machine gun, but you need the sniper rifle to hunt for food more than for fighting as you trek across the Canadian wilderness while your friends get inseminated and ripped apart by alien freaks of nature.
Again, the game does so much right.

I wish I could get into it more.