Black Falcon
I think he was sued by Marvel's (actually black) Falcon and forced into retirement.
Black Vulcan
Wasn't he the First Officer on Star Trek: Voyager?
Blue Falcon & Dynomutt
Still travelling the country and making mall appearances with Captain Caveman and Jabberjaw.
Hawkman
He's been rebooted about five hundred times. As you read that last sentence, he was rebooted again.
Apache Chief
Went into the casino business. Also started a clothing line for really, really big men.
Drucilla - Wonder Woman's sister
Had an affair with John Travolta in a honky-tonk bar, then contracted a fatal illness that at least brought her closer to her mother Shirley MacLaine.
Red Tornado
Still bringing a shine to kitchen floors everywhere. No wait, that's the white tornado.
Ralph Hinkley
Faded into obscurity when perms for males fell out of fashion.