didn't think i was gonna get on today! lmao
anyways...
the harlequins, from what i hear, have great personalities, and are a big favorite to hobbiests, since they tend to mix well with almost everything
bleeding hearts (though i've never owned them) i would assume would be around the same as my rosy tetras. I love how they swim, but they're easily impressionable! since my rosy's got mixed in with the serpaes, they act just like them now !
pearl gouramis, i find, tend to be rather good, depending on if you pick a good one or not. most of the time you can pick out a good one just by colouration (bright, and healthy looking), the fins (rather nice, and trimmed, not torn, or atleast in many places) and by the shape of the fish itself (i've seen many that looked more like a balloon variant of the original)
regular neon tetras, around here anyways, i find one of the best surviving fish out there! they've survived everything my dad had in his tank for over seven years now! including fin rot, body and fin fungus', and many other diseases that only seemed to slow them down temporarely... but black neons i would not be 100% sure... but it'd be a good bet that they'd be nearly the same, if not completly.
and if you want to read this, i'll give you some other options for fish...
for space fillers (as i like to call them, like tetras, rasboras, etc.) you could have many possibilities, some other possibilities are danios. these guys have amazing personalities, like to swim in schools, and depending on the species, tend to be very active, so they're fun to watch.
I've had experience with both zebra and giant danios. Giant danios are a little big, and do take up a lot of room, but they're pretty cool to watch... one giant danio i'd say would equal about two tetras, but at a good 4", they're pretty cool to watch. Zebra danios, on the other hand, are nearly the same, less aggressive (giant danios tend to go nuts over food!), equal the same as a regular tetra (waste) but are a lot more active and interesting to watch. These guys were one of my favorites growing up!
Bottom feeders are some fish I really love watching them. Corys may be some of the most active and fun to watch, but i find they're way too common, and i like to have fish that not everybody (except for people like on the forums) would have... Like loaches!
kuhlii loaches are some of the coolest cleaners i have EVER owned... I currently only have one, and they are nocturnal, but they, i find, are rather durable, different, and deffinitly, without a DOUBT full of personality and spunk. I've been working on cleaning another tank (not coming along so well) so then i could set up an asian theme and include the kuhlii, and get him some friends, but it's still really awesome when he does come out, and watch him zip across the tank. These guys tend to become more friendly and more courageous as you add more (probably only anywhere from 4-6... possibly 8, in your tank) and they'll, even though nocturnal, will slowly come out during the day, and eventually during feeding. I love them because they look like eels!
Also, if you're looking for great personality, and something you could even interact with (through the glass at least) you could try cichlids. Smaller, friendlier cichlids are best to start off with. Such as what i have, a convict cichlid. Just, if you decide to get a convict, make sure that if you get more than one, that you either keep it all females. one male in a community tank, or one female in a community tank is fine, but two males, and prepare for a fight, one of each, prepare for insta-breeding and highly territorial fish!
There's quite a bit there for you to read! lmao