Looks like most every one is picking some of the common cichlids that are available.
I say common, because red devils, green terrors and even dovii's seem mostly available at lfs.
I have looked and asked this question over the last year. My conclusion is not based on experience its, based on the questions that i have asked on various forums over time.
Umbe,
Gets big, i believe 18" - 22" easily requires 180 - 220 gallons, and will reportedly kill anything and everything placed into the tank with them, even potential mates, usually you will go through several females before a success breed. They will try and comr through the glass to try and get you. Difficult to come across at lfs, not alot of people have experiences with them, will bite hands and fingers, from what i have read, they want space, territory and to be the only fish in the tank
Fastae or Red Terror,
Around 12" - 14" fascinating red, yellow colors, pretty dang mean, and wont tolerate, tank mates, most likely will kill selected mates, attitude similar of the convict, especially during breeding, difficult to come by at lfs, not alot of people seem to have experiences with them
from what i have read, they have their territory, and like to be the dominant fish in the tank, they will try to accomplish this as it gains size.
Dovii,
I have read in smaller tanks they will kill most things, but once they hit larger tanks, they become somewhat docile, they are large, and bad looking, but in general, all they want is space and territory
Now, i do have a red devil in a 55, and he attacks the gravel cleaner, actaully anything that i stick in there for cleaning, it makes runs at the glass, and just has a chip for sure. He wants to be the only fish in this tank, i have not tried placing him in the 150 with the oscars, i may someday, but for now, he is ok in the 55
All of this is just my opinion based on what i have read.