My favorite joes have always been Shipwreck and Sgt. Slaughter.
Shipwreck because he was a smart-alec and Sgt. Slaughter because he was just so badass. It also helped that I didn't know he was a wrestler at the time so after seeing him in the cartoon, I then see the real him in toy ads and cartoon promos and i'm like "HE'S REAL!!" and that always stuck with me
My favorite troops would have to be Vipers and Crimson Gaurd. They both look awesome and are the best at what they do. Being the basic grunts of Cobra, Vipers are the best for army building and the Crimson Gaurd just look plain awesome.