Spoilers: All of Season One, and Visage in Season Two, mention of another appearance in Season 4.
Whitney Fordman was one of the original characters conceived in the Smallville series. He appears in the pre-filming novelisation of the pilot as Whitney Ellsworth - personally, I like Fordman better. He doesn't come from the original Superman canon, and much like Chloe Sullivan became popular because of who he was, not because of past associations with his character.
The first glimpse of Whitney is as the golden boy of the town. His girlfriend is (arguably) the prettiest girl in school, and he smiles and is kind to the underclassman, Clark Kent. Then we see him on the football field, practicing, and in an intimate, sweet scene with his girlfriend. All of this presents him as a basically good person.
The next two scenes are a little less nice. First Whitney witnesses an innocent exchange between Clark and Lana which triggers his jealousy. Then he puts Lana's Kryptonite necklace around Clark's neck and hangs him up like a scarecrow - which is a Smallville High tradition. Not the nicest thing in the world - as Chloe says, "years of therapy waiting to happen."
His next scene with Clark, in the second episode, Metamorphosis, is again less nice, with his trying to pass off the scarecrow thing as a joke. Not very funny when someone who was not an alien could die.
Soon, though, Whitney has other things to worry about. Another, less kind, person is after Lana, and he tries to get Whitney out of the way by destroying his truck. Whitney is trapped inside it, and if it weren't for Clark, he would have died - Clark saves his life, ironically. It's after this that Lana finds out and is, naturally, not very happy with Whitney. Tellingly, later in this episode, Whitney tries to apologise to Clark. Unfortunately, Clark happens to have sped off to rescue Lana - hardly either character's fault that it wasn't heard, and I think Whitney would have tried to apologise more than once.
In later episodes, we see Whitney being sweet and kind to Lana, and dealing with the repercussions of his father's illness and death. He has a lot on his shoulders for such a young man, and deals with these things very well, considering.
From the young man who seemed to have it all in the pilot, he has relationship problems, family tragedy and finding his purpose in life happen to him over the course of 21 episodes.
He has a wonderful and complex character arc, not something every character in this show can say.
In Whitney's last appearance as a regular character on the show, many things seem to come full circle.
He goes on a picnic with Lana, and tells her he's going into the Marines, telling her that his father was in the Marines as well. There's a wonderful scene where he says that he thought his whole life was in the football trophy case, and now it seems trivial. Whitney is a man, he was a boy at the beginning, with all of a boy's insecurities. He loves Lana, enough to give her one more dance. It's the most romantic scene he appears in, dancing in the middle of the gym, decorated for a dance, in ordinary, everyday clothes. You have to love a man who can do that.
He's a brave, wonderful man, enjoying his last moments with the girl he loves, and it's a sad thing for him to be leaving.
His last scene, though, is the one that proves how much his character has changed. He asks to speak to Clark alone, and apologises to him, saying it's been a weird year. Then he asks Clark to take care of Lana. The Whitney of the pilot could never have said that.
A kiss goodbye, Lana giving Whitney her necklace in another nice parallel to the pilot, and that's Whitney's last time as a regular on the series. Semper Fi, Whitney. You are missed.
Whitney is seen twice more the series, as a soldier in the teaser of the episode Visage, though he's mentioned several times before it, often by Lana, Chloe or Clark. He is declared dead in this episode, and it's a painful time for the other characters, especially as someone with the ability to shape shift (Tina Greer) impersonates him for part of it.
He makes a brief appearance in the teaser to the Season 4 episode Façade, and to date that is all of his appearances on Smallville.
Why do I like Whitney Fordman? He was a changeable, adaptable, and most importantly *interesting* character. He had some great scenes, was a sweet guy most of the time, and he loved Lana - unconditionally. That's a pretty amazing person.
His death is sad, but as Garth Brooks said, I could have missed the pain, but I'd have had to miss the dance. And the dance of knowing Whitney as a character was worth the pain of losing him as a character.
There actually is a Whitney fiction archive, First Down. It's mostly slash (not that there's anything wrong with that), but there are other stories available. http://firstdown.slashdom.com/
There are also several stories featuring Whitney on the Smallville all-genres archive, Level Three. http://www.smallvillefanfic.com/