Craig the predator fish are the best and funnest ones to keep (the 1's that feed on goldfish)
ive kept all sorts, had a big 6foot australian native freshwater predator tank consisting of MURRAY COD, YELLOWFIN, PERCH, SNAKE HEAD GUDGEON, SLEEPY COD, TANTANUS CATFISH and they all grow BIG, when it came to feeding time it was a BIG frenzy all you could see was gold scales haha
but the best fish 2 keep are SARATOGA (AUS VERSION OF AROWANA) and BARRAMUNDI
BARRAMUNDI have lightning response when it comes to feeding, had 4 foot long ones in the same tank