Non overly aggressive mbunas

yellow labs are not aggressive. acei seem docile too. i have had luck with red zebras too. i have had 6 of them and none of them was overly aggressive. IMO

Yellow labs are the most peaceful mbuna I have kept so far.

I would say acei, otherwise they can all be terrible.

Iodotropheus sprengerae (Rusty) is a calm fish. I keep those, yellow labs and white tailed Aceis in a 125, with no problems.

I kept yellow labs and yellow tailed acei, it was a good match for me. Plus the contrasting yet coordinating colors looked fantastic together.
Everybody who saw it that was not into fish themselves commented that it looked like salt water fish.

My red zebra were more aggressive in general but some individuals were ok

Stay away from : maingano, kenyi, bumblebee, and any of the melanchromis species such as auratus or a fish LFS label as electric blue african. labeotropheus are also pretty aggressive, at least the one i have is.

I'm definitely going with Acei. My Aceis seem to be the only ones in the tank who never chase anything, nor are they ever chased. It's like they don't have their own territory, they just follow each other around the tank. All the others have their territories staked out. The Aceis are actually one of the biggest ones in the tank too. One of my kenyis only keeps other fish out of his territory or grazes. The other kenyi seems to just pick fights with the male bumblebee.

Yellow labs, acei's, rusty's are the most common least aggressive. I would have to say the next batch would be saulosi, afra and fuelleborni..

when trying for afras be careful not to get tropheops. They can be a little more difficult, and they can also be confused with afras when full grown.