Sorry nobody replied. VT are probably the "easiest" Betta tail type to find; Most stores have them. Next to that (at least in my location) is a CT. Most popular *show fish*? Probably the Halfmoon or Halfmoon Plakat, but I've seen all types. Red and Blue are some of the most common colors, and you don't see Yellows, BSE Orange/Yellow, and some other odd colors. That's about all I can say, I've only been to a single IBC mini-show here.
Lucifer, Gabriel, Titan, King, Finnegan, Fin-again & Ricky.
Lucifer & Gabriel are my only non-rescues...