Hey,
in my tank i have 6 bristlenoses and they are all very active and it is quite a cool sight to see them feasting on some zucchini. Some other tankmates that might be good are; silver dollars and spangled perch. my mate, who i bought my tank off, had 2 dollars and 3 perch and 2 oscars in the one tank with no fights whatsoever, one day, however, he decided to be an idiot and drop a lure into the tank (he's fishing mad like me), and the oscar SMASHED it and it went as far down his throat as he could get it! unfortunately, it died during the lure removing process... The other oscar lived veeryyy happily for another 3 years with it's unusual tankmates, my friend new very little about healthy fishcare and the tank was definitely too small for that amount of fish and the filter was only a tiny one.. he had no biological filtration either haha, it was a miracle his fish survived as long as they did! just another example of o's hardiness. OF COURSE, it would have to depend on your oscars personality.. Also, i have heard of oscars being very happy with piranhas and mangrove jacks. Hope i helped, they might be some more colourful, unusual fish that you might consider, and they are definitely very active.
