One fish for a 20 gallon long?

[Crabcake]

Hey, I have a 20 gallon long tank and am looking for a single (or maybe two) fish for it.
I already had community fish for 3 years, and wanted to try something new.

not a big fan of bettas, paradise fish, or Gouramis (sorry betta lovers).


Thx guys!

 

[BigRedsReefs10]

You could do an apisto pair of harem, tons of options

 

[SaraB]

Well you pretty much dismissed almost every option you have for a single fish in that size tank. The majority of fish prefer groups or schools.
Unless you wanted to switch to saltwater you may end up with a group of fish anyway.
What ate your thought on invertebrates/frogs. I'm sure there is a crayfish or you could do an African clawed frog (they get bigger than dwarf frogs).