My love for Rodney McKay didn't start until Atlantis --- but I recently rewatched his scenes in SG1, and I liked him a lot more --- particularly in Redemption...

I think when I first saw him in SG1, Carter was the expert, so I didn't like that this guy just walked in and immediately started questionning all of her decisions... but in retrospect, his points were all completely valid.

Anyway, Rodney McKay is love! :D