Very hard decision to choose one favourite - I have lots of fish and love them all but I suppose I am drawn to a particular few - I love my purple female Betta and blue male VT Betta, my two gorgeous Pink Convicts (even though I thought they were severums!), pair of pretty German Blue Rams and my very well-behaved RTBS.
I would be upset to lose any of my fish - but I know for sure I'd cry if/when I lose any of the above!
Athena