Ironman (or men, depending on however many they decide to milk), Iron Spidey, Cap, Black Widow, and Hawkeye.
The rest of the lineup I will need to see first before I decide, but the ones listed above are definitely on my want list. They are different and unique enough from past iterations to warrant getting the upgrade.
I'm just going to say all of them and whittle away the ones with less effort put into them as they're revealed. The big question here is how many will they make?
It seems at least some costumes will be reused in other surrounding movies. (black panther? ant-man/wasp?)
The only one I can say I'd pass on for sure at this point is Hulk, but that could change.
The longer I go without ordering new figures, the more comfortable I get with winding down my collection.. but at this stage I'll be looking at keeping up with each Thor, Loki and Scarlet Witch released.. Possible I could one day go for a late era Iron Man to complement my beginning (3), Phase 1 (6), Phase 2 (43) lineup, but early promo teasing from the movie almost looks too organic for my liking..