I've been watching smallvile for a few years, never bothered to check out stargate atlantis (I havent watched SG1). I recently started watching it during the writers strike, and I find it so much more enjoyable than smallville (except perhaps for smallville S1,S2). Its light, but they dont dumb down things too much. The special effects are good too.

I'm surprised Stargate Atlantis isnt more popular.

I enjoy Atlantis and its characters but it has its bad episodes, though nowhere near as painful as Smallville's bad episodes. It's nice that it's not as dark as BSG.

But I wouldn't call any of them great shows.

Atlantis took the Stargate formula and dropped the drama and character development and just left the action. Which is fine, action is fun, but not much substance at the core.

Based on that, I'd give the edge to Smallville. It has characters you love/hate and the action is secondary. There appears to be more depth to it. I do agree with Ranger, even though both shows have their stinkers, I don't think anything on TV touches how awful Smallville's stinkers are.

Smallville and Atlantis both have great arc episodes but a lot of the individual episodes are not very good.
I prefer Smallville a bit more.

I started watching Atlantis since the pilot, without having seen 1 episode of SG-1. It was a relatively easy show to get into.

I would say Atlantis has more of a cult than mainstream following. I mean it's on the SciFi channel and probably gets no more than 2M viewers a week.