I have a trigon 190 and the most active fish/fun fish I have in it are 3 Siamese algae eaters, 2 yo-yo loaches, loads of danios an angel and ellioti cichlid.
I also have two big rainbow fish but personally think they would prefer more space/friends. If you go for smaller rainbow fish like threadfin rainbows or praecox rainbows it would look very active and colourful.
I've tried to avoid tetras as IME when they are relaxed they tend to sit idle in the water not moving much.
The problem I have with my tank (well, actually I quite like this feature) is the extra depth to the tank and all the hidey-holes and plants I have means that I rarely see more than half my fish at the same time.