Being almost as old as the engineers I have the following Halcyon kits
Facehugger (built up but awaiting re-paint)
Chestburster boxed
Queen chestburster boxed
Attacking Alien boxed
Alien warrior (built up but awaiting re-paint)
Narcissus shuttle built up
Space jockey (built up)
APC built up
Dropship built up
Sulaco (built up no paint)
Predator 2 (built up)
Power loader (built up)
Alien Queen(built up)
Alien 3 creature(built up)
Most of these I've had for over 20 odd years,The Dropship and the APC are the sort of kit that fight you all the way
For my money the Alien 3 creature is a fantastic injection kit in a wonderful running pose,perhaps the best kit they made,I would love to get hold of the Nostromo,but its so expensive!
The big alien figure (in bits in the cellar)