I've tried to resist this line, but haven't been able to. I'm not being a completist by any means, as I'm opening my Joes up and considering making a photonovel of the Joes attacking Cobra Island (similar to the original Joe comic). I've even considered buying this for my Cobra base and painting it -

Anyways, the Joe stuff holds a special place in my heart - my first real customs were when I was a kid in the mid 80s with my figures, doing basic head swaps - and I also used to use my parents' camcorder to make little fan fiction movies with my figures - in a sense those were the foundation of the photonovels that I now make with Star Wars figures.
So far here's what I've bought in stores (and opened) -
5-pksCobra Series 1 - x 2
Cobra Series 2 - x 1
Joe Series 1 - x1
Wave 1Cobra Commander x 2
Snake Eyes x 1
Storm Shadow x 2
Flint x 1
Cobra Officer x 4
Wave 2Serpentor x 1 (would never use this in a photonovel though, he's too silly looking)
Cobra Trooper x 6
Lady Jaye x 1
Beach Head x 2
I'm thinking about getting a few more of the Beach Head figures and doing head swaps with other characters from the Joes for my photonovel, if I ever get to it. I just think that most of the assault team would have the same outfit. I might even create a couple of fan fic characters too.
Looking back at the old days, my favorite figures were Destro, Cobra Commander, Cobra Officers, Crimson Guards, Storm Shadow, Snake Eyes, Hawk, Crazy Legs, Flint, and Outback. I really didn't get into GI JOE until 1986, and stopped in 1990. But that was a very fun period in my life, I liked GI JOE a lot better than Star Wars when I was a kid.