For a beginning superhero, Spider-Man was quite capable. In Amazing Spider-Man #5 (Vol. 1) he holds his own against Doctor Doom, who first attempts to recruit him for his war with the Fantastic Four. Spidey refuses, and Doom declares him an enemy. Later, Doom mistakes Flash Thompson for Spider-Man, and Spidey has to go rescue him. There's no clear winner, but anybody that can hold their own against Doom has got some serious stuff as a superhero as far as I'm concerned.