I know you said you don't like geophagus but
http
/media.photobucket.com/image/geophagus%20surinamensis/markandhisfish/eart.jpg
I just got myself 6 of these (well, altifrons not surinamensis, but essentially they look the same) and they are lovely!! If you don't want to spend much you have to get them quite small, and they don't grow that fast I don't think.
Have you thought about opaline/blue/gold gouramis? All the same species and make very nice random pretty coloured fish. I have 5 in my 6ft with no problems so you could get away with a lot in your tank.
They will also breed for you - mine have started making bubble nests.
Bristlenoses are nice little bottom dwellers, but beware - they WILL breed and you will end up with a lot - if that doesn't bother you much then you should get some. Note you can get them in albino, calico and longfin and any combination of longfin + colour, so you could get some good-looking fish even if you do settle on BNs.
Umm ... do you like rams? If your water is soft and acidic enough you could get some rams - they are very nice fish.
I'm running out of ideas lol - what about some small cats too? Or one or two medium sized cats?
Also - a sharky! A ruby shark or something just for the presence really.
I could really have a field day with a tank the size of yours