oscars are great, most amphilophus, parachromis, and butti if we are talking cichlids. my giant snakehead was wicked and seemed really clever, i felt as though he was plotting to kill... i sold him before he outgrew my tank and now have a dwarf blue rainbow snakehead in my kitchen in a 40l, he comes out from hiding when i go out there, comes up to the glass when i tap the tank... really growing on me that little dude, didnt think he'd match up to my old giant but he is prob better... im guessing all snakeheads are cool and full of character. my silver aro 'harry' is also a character and is always watching me, he looks excited when he sees me moving. manny piranha i had had a wicked evil personality, imo once they hit 5inch coolest piranha by far, glass biter, make tank maintenance very difficult.