I have to say that Lionel and especially Chloe were really the reasons why I decided to stick around along with Michael Rossenblaum's excellent portrayal of Lex Luthor. If not for these three I think I would have bailed on the series really early on.
Before I answer the question you threw out, let me just ditto what you said there. Ally, Glover and Rosey were truly the glue that held this show together (with help from John Schneider and Annette O'Toole). We all know my obsesion with the Chlovage, so I won't go any further that what I just said.
With that out of my system, SV was actually in the middle of it's third season, when the Missus and I first discovered Season 1 running on Lifetime or some other obscure cable network. I had heard of the show, but had never watched it, primarily because at the time, it ran at the same time as 'Enterprise'. But we both kinda got hooked watching the re-runs and shortly afterwards found Season 2 on DVD for a really good price. Once S1 ended on cable, we immediately began watching the DVDs and have stayed with the series, for better or for worse, ever since.
I hope most of our regular gang chimes in on this thread. I'm curious to see when everyone else discovered the show.