It's how funny how you avoid the "hot" show sometimes and then find then love them in the reruns. Frazier is a good example of that from me. Never really saw it first time when it was on, then a saw a lot of reruns and the writing/acting was so strong.
I never watched ER when it was sort of "the show" either.
I watched it for a short time after George Clooney left, until Anthony Edwards left, but oddly that was it.
Over the years, I also found many favorite British shows in reruns usually on PBS, including : Are you being served? Absolutely Fabulous, Monarch of the Glen--all gems I felt like I discovered.
I never watched Sex in the City, even when we had HBO for a short time. It made me nervous/struck a nerve with me.
Even though many of my female friends who were very different from both me and each other loved it. I guess I just didn't "get" it.
I have friends who love watching "Lost"--never have seen it.
Also folks at work love "The West Wing" and "24" have never seen them. I feel like it's too late to get into them now.
Back in the day--I heard about "Seinfeld" when out of college/working, and started to watch it, but then enjoyed discovering/catching up on episodes in reruns too.
Generally I do not watch and have not seen Law & Order and all the spin offs, or the criminal investigation shows, CSI, Cold Case, etc.
Never saw "That 70's" show first time out either, now seeing the reruns on F/X and finding them goofy/funny now.
Lately I think I'm going into an escapist from reality phase watching TV and starting to watch to more sci fi shows, which was never my thing in the past.
I never watched Buffy or Angel, even though I had some friends who were fans and devoted, et al.
Started to watch Stargate SG-1 on SciFi network a couple of years ago. I had never seen the first run early shows on pay cable in the late 1990's I forget if it was Cinemax or HBO, but I never saw them there or for the time they were only in syndication. I was able to catch up and get into the show via SciFi's reruns and also recent season reruns that still air in syndication before reverting to Sci Fi reruns. With the recent additions of actors Ben Brouder to the regular cast and Claudia Black as a reg. guest star via the wires, et al., I've heard a lot about their previous show "Farscape." Actually I heard a lot about it with the mini-series/movie wrap up to the Farscape series. There was a lot of contention (from the fans) when the SciFi network at the time cancelled the series. Anyway, our local Fox affiliate is now showing "Farscape" late at night on the weekends, so insomniac that I am, I saw the 1st episode/pilot from 1999, just last week. And I have to say hmm, intrigued so far and going be watching this now too, and I think I can file it under rerun discovery I never watched first time around!