I actually think that seasons 3 and 4 were FAR FAR FAR better than the first 2 seasons. THe first 2 seasons were CRAP!!! It was as though they only made one single episode and kept editing it to make another episode
Take the case of Sam Jones III, who played Clark Kent's best friend, Pete Ross, on the first three seasons of Smallville. Gough explains that in Season Two the character didn't seem to have a function on the series, so the writers added a plot twist and had him learn about Clark's secret superpowers. "That served us for, I think, a season," he says. "When we got into Season Three, we just found that as we started to break stories, we'd sit in the writers room and go, 'Okay, where's Pete?' Clearly it was a character who we couldn't service on the page. So what he ultimately became was a cautionary tale for Clark, which is, if you tell somebody your secret and you give them that responsibility and they can't handle it, you're going to lose that friend, in a way. So we had Pete move away."
Cast chemistry also played a role. "You look at the chemistry of the cast, [and Pete] was never somebody we could use in a love triangle, either," says Gough. "That was just sort of the nature of the actor we cast and the chemistry between the actors. It was hard to get him into any sort of romantic story, and then, after a while, we didn't have the plot elements to service him, either."
On Smallville, there have been a couple of regulars whom producers envisioned as part of the series for just a season or two. One of those actors, Jensen Ackles, played mysterious Jason Teague last season. "When we first sat down with Jensen, he said, 'Gosh, I don't know if I want to go on a series and be committed for however [many] years you're going to be on the air,'" remembers Gough. "We said, 'Jensen, to be perfectly honest, this is probably a one-season arc, maybe two. I'd like to leave it open-ended. We see this season, but I don't quite see where you [fit in beyond that].' But we never know. You start breaking the story, and the character pops, and you find things to do. It ultimately ended up being a one-season arc because he played into the over-reaching plot of the season. By the end of the season, [the arc] had played out, so he got hit by a meteorite."