I have Sun but I can't decide between springing for Ultra Sun or Ultra Moon. Can someone help me with my decision??
I have Moon and am going to get Ultra Sun since it will be a fresh new game with different version exclusives. So in your case I'd recommend getting Ultra Moon!
I'd get Ultra Moon if you had Sun and Ultra Sun if you had Moon. That's what me and my friends are doing. EDIT: Actually I'm getting both, but I'm using Ultra Sun as my main as I had Moon as my main last time.
Check out the version exclusives, that usually helps me decide. Or even which Gen 3 boss you want to battle! #MissingNo
If you can get version exclusive legendary Pokémon like with Solgaleo/Lunala and Ultra Beasts in Sum/Moon then it wouldn't matter really. I'm only going with Ultra Moon because I had Moon before.
Moon because the Legendary I found more creative in design and the pokies you get are more justifiable. For Sun I disliked the version types you got. Felt like it wasn't worth the buying effort.
I'd suggest choosing the version that you didn't get previously. I got Sun, so I'm choosing Ultra Moon once it comes out.