At the start of season one, Clark Kent (Tom Welling) is a young man with superhuman abilities that's trying to figure out his place in this world after discovering he's an alien.  Throuhout the seasons, Clark Kent is slowly becoming more and more Superman, discovering his abilities as time goes on.

At the start of the show, Clark is friends with billionaire Lex Luthor, whose life he saved.  Of course, later on Lex would go on to become his nemesis before leaving the show

Clark has had an on and off again relationship with Lana Lang and in the latest seasons, fans have been hoping for a Lois and Clark finally.

Now, Clark works at the Daily Planet and is forced to meet all sorts of fun villains from the DC Universe.

Clark Kent Quotes

Clark: I told you: there is no Clark Kent.
Chloe: No disrespect to your Kryptonian calling, but coming back to feed the dog is about as human as it gets.

Clark: Isn't it time we moved beyond these mental trials?
Jor-El: Your determination is strong, Son, but just as your passion will be your greatest strength, so, too, will it be your greatest obstacle.

Smallville Quotes

Zod: Unlike you, I will lead from a throne, not from the shadows. Every human, including the woman you love, will kneel before Zod!
Clark: You already destroyed my first home. I won't let you take this one.

Nixon: It seems you've given out gifts to the competition. Now, we had an arrangement. You give me stories, I give you information. Now, what did Carrie Castle do for you that I couldn't?
Lex: She gave me a pretty mean shiatsu massage.