It was a toss-up between Knickerbocker's Ringwraith and Alien, but http://actionfigurehalloffame.com/I voted for Kenner's Alien figure because (in my opinion) it's the best designed and detailed figure on the list...

I hope this link works; never done this part before...
http://actionfigurehalloffame.com/

I should say that the site is a little confusing, so just click on the menu icon in the lower left side and go to Vote...pretty easy after that...

First figure I thought of was Kenner's Big Chap Alien, so that's who I went with. Some decent choices on the list (Warduke!), and some major historical choices (the original G.I. Joe, Captain Action), but a lot of random-seeming choices, as well. And nothing after the 80s? Pretty unfair to Spawn, ML, DCUC, MOTUC, etc. Unless there's a different bracket?

They said the only requirements were a toy and a minimum age of 25 years old to qualify.

Ah, it's the Rock 'n' Roll Hall of Fame rule. Well, it's a pretty solid list for the most part, despite some oddness (Boss Hogg?). It could use She-Ra, because the hybrid doll/action figure idea, bridging the gap between boys' and girls' toys, was pretty remarkable.

I would've also thrown in...
TENDRIL from Inhumanoids! One of the easy best of all time.
Bravestarr
Centurions - any.
C.O.P.S. Buttons McBoomBoom
Kenner Robocop
Major Matt Mason - any of the aliens.
Matchbox Maxx FX Freddy Krueger
Mattel Pulsar
Mego Planet of the Apes - any ape.
MTC Nightmare Warriors - any.
Power Lords Adam Power
Remco's Crystar
Rom the Space Knight
Shogun Warriors - Mazinga, Godzilla, any of these awesome things.
Spiral Zone - any.

Some of the choices are hard to distinguish from other figures in the same line. Storm Shadow vs. Snake Eyes is a toss-up, as is Leonardo vs. the other Turtles/Shredder/Splinter/Krang. It's interesting they they also went with a repainted Robotech toy for their Transformers choice. I might also substitute Skeletor for a MOTU figure that more exemplifies the weirdness of the line, something with a crazy action feature or wild design (Moss Man? Modulok?).

Heck yes +1 for Buttons McBoomBoom. Totally agree with you on the MOTU figure design weirdness. Lots of funkier choices like King Hiss, Sssqueeze, Blast Attak, Extendar, Dragstor and Snout Spout come to mind.

Yeah, it felt like they went with a lot of really odd or easy choices for the list, but there's a few really excellent ones. I've been pretty remiss in forgetting Super Powers Wonder Woman on there, as she's one of the most important female figures of all time - she was one of the figures that made it okay and even necessary to include female characters in a boys' line. I mean, Secret Wars didn't even have Storm, and that's during the beginning of the X-Men's run as the most popular comic book team in the world.

Also, I don't know if they'd count it as a figure, but Tiamat from AD&D would be an awesome choice.

If I had to pick ten from the list provided (that's how many are making the first class), I'd choose...
AD&D - Warduke (easily the best 3 3/4" on the list)
Alien - Big Chap
Captain Action - Cap
GI Joe - Original Joe
Henshin - Takara
Micronauts - Antron
Shogun Warriors - Gaiking
Star Wars - Boba Fett
Super Powers - Wonder Woman
TMNT - Leonardo

I mean, it's a tough field, but I went with the coolest and mixed in some of the most important (no way does Joe or Captain Action get left off. Way too important. Same with Boba Fett, actually, between the rocket controversy and the impact the figure had on his popularity and ultimately the franchise itself). My concern with the list is that the importance of some lines is going to overpower the specific figures.

Also, what an underrated figure that Lone Ranger one is. That's just a killer figure for that era.

Vintage MOTU & TMNT all the way!