Me personally, will say Convicts.....because i've done it sucessfully.
I'll be one who disagrees with cons.
I can barely squeeze my pair into a 40gl tank.
I had a pair who took over an entire 80gl.
I have adult cons, however, females averaging 4", males averaging 6".
Still, I've kept cons in tanks as small as 10 gallons. It just wasn't a permanent thing. Might work up till they hit about 2". Then it's a situation that amplifies domestic disharmony and can cause it to become fatal for one of the two fish of the pair.
I'd say the same for kribs. It simply does not work as a permanent situation.
Smaller Apisto. species, blue/gold/German rams, Lamp. multies, L. similis and L. brevis are about all I can recommend as far as an enjoyable 10gl cichlid display goes.