Point blank: One of the best over the top super villains in comic books. And it works BECAUSE he's so over the top. The speaking in the third person, the ego, the quest for total control, genius, the vanity, the total badassery, the code of honor mixed with the willingness to do ANYTHING... Yeah, Victor is one of the all time greats. (And I love that Reed usually starts off with any meeting with Doom by calling him Victor. It's always come off as kind of passive aggressive to me. "Victor, it doesn't have to be this way" or "Victor, what do you hope to accomplish by this?" It's like Reed is saying "Yeah, I know... You are DOCTOR DOOM. Monarch and Super Villain supreme. But to me, you'll always be Victor, the dude that couldn't see how he'd screwed up his calculations in college.")
I really liked Kirby's take that Doom was actually the possessor of only one tiny scar under the mask. That he was such an egomaniac that simply one small flaw pushed him over the edge. That's the interesting thing about Doom to me. All that bluster an in reality he's just a guy with a fragile sense of self because of his obsession with perfection. I also am of the mind that his competition with Reed is totally one sided. I think that when Doom goes to sleep at night it's with the thoughts of how he can't stand that Reed might be smarter than him and is given plaudits and praise by the wider world. I think when Reed goes to sleep at night Doom is the farthest thing from his mind. (And seriously if I was going to bed with Sue, I wouldn't be thinking of a guy named Victor either.)
But Doom is also a force to be reckoned with and of all the villains of Marvel, I would take his assessment of the heroes more seriously than any other. He's just a great villain for any hero to go up against, and the more epic the hero the better, though there's also moments like when Spidey or Luke Cage cross paths with him and it turns out to be a winner of a story as well.
All in all DOCTOR DOOM is that rare old school super villain that's still got it in the 21st Century.