I probably answered this already, but for now, having seen everything we have, it's really dependent on who comes out and how much I like the film.
Want:
Mantis
Gamora
Nebula
I doubt we'll see them all, but I'm holding out hope for Gamora especially (I'm happy with my GotG Drax and GotG2 Starlord and Rocket).
*IF* what we've heard is true about her in the film, I'd expect they'd have to release her.
Not sure if I want, depending on the film:
Teen Groot
Thanos
I have a feeling that we'll eventually (maybe by GotG3?) see a "won't change with every film" version of Groot. And in theory, I'm quite happy with baby Groot representing him on the shelf. But if Teen Groot is cool enough in the film...maybe.
As far as Thanos, I want a representation of him from his "final battle" at the end of his arc. But until I see the film, I don't know if this is it or not. With all the time bending in the next one, will that come with a Thanos variant? And one that looks closer to his "standard" look? Or will his armor actually show up in this one, as we've seen in some promo stuff/figures/LEGOs? I might end up waiting for that one, depending...
No interest in Iron Spidey (I'd rather have him in his iconic look), Butterfly Iron-Man, Grungy Cap, Black Ops Thor or Blonde Widow.
Personally, I'm much more interested in the potential Avengers 1-era upgrades/redos we might see with the next film. I still feel like that was the pinnacle of the MCU.