There is actually another member of the Circus of Crime. R/LE Princess Python/Zelda Dubois. I know it wouldn't make for a great team, but he's not the only one.

Icons Superman(veteran)

Omega Red.

What ticks me off about him and the first run of Black Lanterns was the absence of the Monster keyword. The Black Lanterns and Marvel Zombies actually play really well together.

Azbats Crisis Convention Exclusive didn't team up with anybody really he got rid of Robin (Tim Drake ) pretty quickly :-/

He hired Batroc and his Brigade in the GLA mini.

I like using Impossible Man to recreate one of my favorite "What If" storylines when they gave the Infinity Guantlet to him and he went crazy with the powers in quite a humorous fashion.

I like teaming 350 Brainiac with Sentinels and Ultron drones in 600 pt matchs, the minions run out, tie stuff up or attack where they can, meanwhile Brainiac waits it out, sees how they are doing and when the time is right you push him to his monster click, if he doesn't get hit to it, and start mopping up the left overs.