But how much of that is unusual for any lead character in an action-drama show? Clark has a tragic past to beat them all, and other Smallville characters with tragedy in their pasts include Lex, Chloe (with her institutionalized mother, and later the death of Jimmy), Oliver, and Zod. Tragic pasts are pretty much a prerequisite for characters in drama.
As for romantic success, Clark, like any TV hero, has had plenty of romantic interests over the course of the series, and so have most of the other characters. The only romantic "failure" (in the sense of never actually getting involved with the object of desire at all, since most TV romances fail tragically sooner or later) is Chloe's unrequited crush on Clark.
As for unnatural combat skills, Lois and Tess certainly qualify as well as Lana. The exaggeration of combat skills is simply par for the course in a show like this, and I always felt that Lana's choice to develop such skills was a logical, empowering development for a character who often found herself cast in the role of damsel in distress. And again, it's rare to find an action-show character these days who isn't good at fighting.
As for popularity, few of this show's characters have ever been wallflowers or unlikeable people. Lex was one of the most popular men on the planet. Chloe might've started out as a bit of a geek at school, but she was well-liked by pretty much the whole cast. Clark has been the center of everyone's life more than he's generally deserved to be (I still say that if any Smallville character really qualifies as a Mary Sue, it's Clark, at least up until the last couple of seasons).
As for intelligence, Chloe and Lex certainly took the cake there. Jonathan and Martha had considerable wisdom to offer, and Tess has a devious sort of brilliance. Lana never struck me as a genius, just a competent person who rose to the challenges presented to her.
The exotic looks are a function of the actress they chose to cast. Lana Lang is traditionally a redhead. If anything, Ms. Kreuk's exotic qualities were downplayed on the show, since all her biological relatives (not to mention Lana herself as a child and an elderly woman) were played by Caucasian actors. And physical attractiveness is pretty much a given for most lead actors in most TV series.
Also, the lead characters in most series generally do succeed at most of the things they attempt, at least when they're the heroes. Or they fail as much as the storyline demands it.
So you're not describing a Mary Sue here, you're just describing a TV action-drama series lead character. Just being larger than life doesn't make a character a Mary Sue. One of the key factors of a Mary Sue, in fact, is that the character isn't really anything special at all; she or he is merely asserted to be by the author, without it ever actually being demonstrated.
