WOW! Tough question!
Here goes (I'm limiting myself to non customized figures):
1. Pokemon Monster Collection #128 Tauros
2. Super Powers Green Lantern
3. DCD Golden Age Flash
4. Starriors Crank
5. Gundam MSIA Old Type
6. ZakuTransformers Galaxy Force Saidos
7. Souchakuhenshin Kamen Rider Raia
8. Microman Spymagician M-142 Hudson
9. Super Powers Firestorm
10. Man-eating Cow
I'm a HUGE GI Joe fan, but for me all my favorite Joes have been customized to one degree or another. Same for Star Wars and LOTR, all my favorites are to some degree customs.
This list of of toys that I love PURELY the way they arrive in the package with no realy modification by me (other than assembly really.)
I hope we see more of these lists, as I find my tastes shift from time to time but I tried here to not purely go with recent toys but combine them with toys that really stuck with me over the years.
(EDIT) GAH! Had to edit my list! Forgot one of my alltime favorites that I still own complete from when I was a kid! Tomy's Starriors Crank! Another great line with Mini-comics. "The Forest" really gave character to that cranky drill bot!