Ahhhhhh those are beautiful :D
I'm afraid you've inadvertently hit my weak spot... pretty fish :O
(of course basically all bettas are pretty, so I end up drawing a lot of fish)
That's it, I'm going to draw these. But first-fish-first-served, so the others will have to have their turn. And it might be a while because right now I have the flu (seriously, immune system? Can you be healthy long enough for me to think straight?) and they've been waiting for like a week. But I will get to you guys!
As for the non-bettas... I have no clue how to draw those
I could take a crack at them, but I'd probably need at least two pics per fish from different angles in order to learn what they look like. I've never been good at just copying pictures exactly. It might look like that's what I'm doing, but what I actually do when I draw is the process I describe in the tutorial linked in my sig, which is quite a bit different and a heck of a lot easier!
(That's why I decided to make it into a tutorial: so that people who were just trying to copy pictures could understand what they were seeing a little bit better.)
Bettas are roughly uniform in shape even if they have lots of individual characteristics, so if I can't see a particular characteristic in one photo, I have a good guess as to what I'm missing. I don't know what's going on with other fish, though, and I also don't have one swimming right in front of me as a rough reference model.
But I will probably try if you give me more pictures. :)