There's also the possibility of roleplay toys. Things like Legacy and Wraith capes, plastic Bunker and AZ masks and Tachyon goggles, watches with the FV logo on them that have little flashlights that project pictures of each hero, wrist launchers that fire plastic 'Razor Ordinance' knives and Flak Cannons with firing sounds...
Not to mention the flood of Halloween costumes.
Hmmmm. I am actually in the early stages of my biggest custom project ever: action figures of every single hero and villain in the Multiverse. I have nearly all the figures that I need for almost everyone except the Citizens of the Sun (Dawn's all set), Biomancer's Fleshchildrene, the FILTER crew, and the gladiators (Kaargara, similarly, is all set). Missing some of the minor villains, too, but I'll get there. But otherwise, every hero, every villain and most of the minor villains, several of the environment targets, accessories, and variants have their bases figures selected and isolated. It's going to be a LOT of work but I'm pretty chuffed about it.
I am in the process of setting up my workplace at my new apartment and organizing so that I can get started in earnest, maybe in the near future I can at least put up some in-progress photos. Once I have time to set up the photo studio on the dining room table, that is.
Thinking about it, I’d probably be super into some of those micro-playset toys like Mighty Max or Polly Pocket - an environment like Freedom Tower or the Tomb of Anubis, each with at least a hero, a villain, and a mook, with some cool little set pieces, I think that would be really amazing.
We should talk… Seriously. Send me an email. craig@greaterthangames.com. 
Edit: To be clear, this isn't scary cease and desist kind of stuff. This is "my major hobby is taking photos of action figures" stuff, and I happen to have a particular interest in photographing Sentinel Comics stuff if it's ever around.
I could picture an Absolute Zero toy that had the color changing pastic sticking out of his hands. So it changed Blue when cold and red when hot to pretend he was shooting frost or flame.
Nano Metalfigs of Sentinels would be awesome.
I'm certain Baron Blade made like... lead-based Legacy toys at one point, to try and ruin his arch-enemy's reputation. That or he sold every piece separately.
"Legacy Longtorsooooooo! Wht-tsh! He's long!"
I once upon a time (years ago, after making my Lego SotM minifigs) converted all known sizes of the (human-shaped) Multiverse characters down to 1:6th scale to make Barbies/Action Men/whatever-your-articulated, redressable-figure-of-your-choice is custom characters, and then created a spreadsheet of closest available bodys and existing doll facemolds for each of the characters (back then there were a lot fewer, obvisiously).
I still have the speadsheet and a lot of the heads, body parts, clothes and accessories, but after I was utterly unable to obtain this one particular head for the Unity doll (unfortunately, that head was only created for one specific doll in one particular line and never reused), I kinda lost my buzz.
Mind you, I would never have bothered with a full Guise action figure. A Guise PEZ dispenser would have done the trick.
I have a half done Expatriette custom based on a Maria Hill figure and some various bits and pieces for other characters.
I should dig them out and actually finish them off some time.