So, yeah.... I think NECA might have me on this line too....
Definitely buying Hicks and Hudson and the Warrior alien. NECA just posted new pics of these painted figures on their facebook page - so awesome! "Aliens" is one of my favorite movies of all time.
As for Prometheus, that one is tougher. I feel like if I go down that hole I will be compelled to collect everything from that movie series as well. I do like the TRU 2 pack, but other than that I am not sure I just want the other characters since they are just standard, human like figures.