I like all sorts, though the only game I managed to be in had my playing as a mix of Firestorm and Metamorpho: he could alter the chemical substances of objects *or* he could alter his own structure (but not both). I wrote a 40+ page comic script for a series about him and a pile of other characters, but got sidetracked before I could get it drawn.
Personally I like playing really good characters, with a strong sense of right and wrong, honor and justice. I GM a lot, so mostly I play villains, but when I PC stuff I try to play good guys.
Powers-wise, it depends on the scale of the series, and the focus: no one wants to be left out of the action (like the Thing in a Flash story). If I could be anyone, I'd want incredible combat abilities plus some sort of other thing, like high tech ability, psychic powers, avatar/bending, or kryptonian whateverwhatever. Something to keep me in the game, as it were.
Cyclops: nope, no military training, just X-men training. He's one of the first class, and has been the leader since, like, 1966 or so, so lots of experience technically. However, he's never been in the military of a nation, with guns and such. You could do him as a Warlord with some Warlock-style blasty powers.