Couple of things,
Tecnically the 6 Million Dollar Man was 13" not 12". Pissed me off as a kid as Steve Austion, Oscar Goldman, Maskatron, even Jamie Summers- The Bionic Woman, towered over my Adventure team GI Joes.
As for Mego, they made 12" figures of:
Hulk
Spider-Man
Captian America (with a freakishly large head)
Superman
Jor-El
General Zod
Wonder Woman
Batman and Robin (Robin was 9" to be in proper "teen" Scale)
RoboCop figure. I got it when I was a little kid. I really enjoyed the movie and looked foward to Robo pulling his gun out of his thigh. I have no idea where it is now tho.
My first 12" figure too. Dorgmal, I would absolutely get one. Unboxed you can get them pretty cheap on Ebay.
In fact, that was the first thing I looked for when Ebay first came out. I lived in Manhattan at the time and there were a couple of stores that had him but for way too much (~$90 in the early 90s was a lot of money!). So when I found out about Ebay, I went straight to Steve Austin. I got myself a couple unboxed ones at first til I finally found a good one with the rubber arm sheath still intact and the figure MIB, with the bionic grip for about $65, which was a good deal of money in 1998. But it was well worth it, believe me. Now I'm just hoping HT, Enterbay or Sideshow make a "modern" version of him.
And back on topic, Indy was my first pre-order but ANH Han was the first figure I actually received, which blew my mind with the details and craftsmanship.
The original 12" Boba Fett where you could look through his head like he was using the drop down visor. I still have a picture of me sitting holding it with awe in my face at around seven years old. One of my best toys ever - long gone though .