I only knew of the few that were on the Toy Archive site, but have since discovered through here that there are more available (such as the Short Rabbit). I've not been really into collecting any but the MOST noticeable variants (like the Blue Jag and Pink Weasel), but some of the others interest me.
* Both Tortoises. Oddly, I managed to end up with both without realizing it! I was considering aiming for the "Orange Base" Tortoise, but a random check of my shelf showed that I had the OTHER one lying around too!
* Blue Jaguar. One seller actually offered me him instead of the Red Jag, but I turned him down, as I actually prefer the red. Of course, I ended up buying his more-expensive Blue Jag later, thus making the whole thing more costly .
* Pink Weasel.
* Orange Gorilla.
* I have "Glossy" versions of a couple: the Shark & Porcupine (with his darker-mustard armor). As a kid, those were the only "Variants" I knew of.
I don't own the "Yellow Headlights" Squirrel, but since I had two Squirrels, I just repainted one's so they LOOKED yellow. I consider that "okay", as I don't plan on screwing a buyer over with a "Fake Variant"- I even painted his OTHER red armor bits yellow so he'd look more-uniform, and not like an actual alternate version.
I don't think I care much for the "Painting Error" ones, though. Why would I pay MORE MONEY for a flawed Walrus or Mouse? I get that rarity is a big thing, but it just comes off as odd to me.
Also: What are you most-desired alternate versions, if you don't have them? I'd love a Black Mole and maybe a Plum Carp, but any "Factory Painting Alteration" is pretty neat to me. Even as a kid, I was kind of obsessed with which version was "better".