Originally Posted by DJ's left nut
Here's what I'd suggest - Rainbows.
They're extremely colorful, like cichlids. They' significantly more docile, though. They'll school better than Cichlids (who mostly just form territories and go to war). They seem to be much more in line with what your wife is looking for. If you're looking for a planed tank, these are unquestionably the way to go. I've had decent luck with them in the past, before I let my freshwater tank go to seed.
Excellent suggestion. Assuming your pH is pretty neutral, I'd pair them with some cool catfish, like these Synodontis.