ogre929 said:"What's the meanest cichlid" ..... what a garbage question. I used to get this question back in the days of the fish trade from the most ghetto of people. They wanted the meanest fish. I'm talking about the most uneducated, ignorant people who asked this question. I got sick of it long ago.
I think some people w/ out much experience wants some ideas of what fish to get. (theres nothing wrong with it). And majority of predatory fish fanatic wants a mean fish. Although all fish has different attitude, but for the most part you can categorized each species to be more meaner than others. For example for the most part, red devils, midas, FH (hybrids) are just glass bangers in aquariums, and most if not all will interact w/ owners and will not tolerate any tankmates.
Another example as semi-aggressive and very interactive fish is an Oscar, but cant be compared to red devils/midas when it comes to aggressions.
However most parachromis species are somewhat shy in nature. But very mean species are Doviis, but can also be shy at times.
So lets say a newbie wants a big fish w/ a wet pet attitude but wants some tankmates for it. Oscar will be one of the best candidate.
But a newbie wants a very mean big fish, that will even attack an owner and will kill anything in the tank. Im sure most will recommend a red devil or midas or FH.
IMO this question is not a garbage, although for most experience hobbyist questions like these will somewhat gets annoying at times, since you already know most type of fish and its attitude. But for a newbie it really matters, to making a good decision.