A lot of them.
Blue Stinger...yes I said it
Kiss Physco Circus
Who Wants to Beat Up a Millionaire
I recall the WCW/WWF games not being very good
Omikron
Wild Metal Country
any of the sarge games
Tomb Raider
102 Dalmations Puppies
Chefs Love Shack
The Grinch
dragon riders
Fighting Force 2 (this was very nearly Streets of Rage 4 as that was it was originally in development for)
Floigan Brothers
Spawn
Soul Fighter
ducati world
I can't think of anymore. I am sure there is more.
I have a soft spot for Spawn and KISS. KISS was a fun, albeit stripped down shooter that could have been much better with multiplayer. Spawn was unbalanced, but still fun on a brainless level.
Tomb Raider 4, though not the height of the series, still holds a special place in my heart. Omikron was better on PC, but I still like it on DC. Flawed, but still ambitious enough to be good. Only worthwhile thing Quantic has ever produced IMO.
Blue Stinger...yes I said it
Is that... a surprise? I thought most people consider it a terrible game to begin with?
I think it's kind of fun in a really doofy sort of way, but still... I thought it was widely thought to be pretty bad.
I love Blue Stinger. Yes, the characters look like they're made of hotdogs. The story and voice acting are horrid. But it does fall into that doofy sort of fun like you said. That, and it was my first DC game so i have mad nostalgia.
Of all the game listed (that i've played) none really stand out as being so bad they are unplayable. The one game that I do see mentioned again and again is Who Wants to Beat Up a Millionaire? I have no idea what the game even looks like, and I don't want to. At least not until I have it in my hands. The mystery surrounding this pile of poo just keeps getting bigger. I need to have it.