Hi I'm new here, but I've collected ML for years. I think for my 10 most I'd have to break it down into:
A. regular ML
1. Series 1 Iron Man - this is a classic and I think that this figure started it all, esp with the removable face plate.
2. Series 3 Unmasked Wolverine - this figure was awesome and started the whole variant/chase figure madness we see today.
3. Series 5 Colossus - I remember picking this figure up and opening it and was amazed at how much he looked like in the comics. Though today I prefer the X-men Classics one.
4. Series 8 Storm - cuz I look at the face sculpt