My first tank was mbuna, still have it running too. I really like the mbuna tank, but I think I'm more proud of my Peacock/Hap all male setup. The colors are just amazing. That being said, Hara (mbuna) are probably still my favorite species. A lot of that has to do with the fact I have been keeping them the longest though. I do feel there is more variety in peacocks/haps. IMO most mbuna are very similar making it hard to find a variety of tank mates. Don't get me wrong though, I LOVE my mbuna tank. It's the only one in my living room on display.
Myself, I like having variety. I have tanks from Malawi (mbuna, peacock, haps) and I also have a Victorian tank. Working on getting my Tang setup as we speak. Next up, maybe some shellies and eventually a CA/SA. Eventually I want to get a SW tank setup, but everytime I get a new tank I can't help but always 'need' another tank and put more Africans in it.