My favorite freshwater fish is the Aussie lung. I will own one some day...
My favorite that I own is my SA lung (I'm partial to prehistoric/primitive fish in general). I think my favorite fish in terms of looks is my flagtail. When I got him when he was about 2", he was silver with striped fins. Now his sides are like mirrors, but his head has some nice red, his pelvic fins are blood red, and all his unpaired fins are a really nice orange.