In no particular order (scripted shows only):
General Hospital
It's the great TV love of my life.
Queer as Folk
Three words: Brian Kinney... naked. Seriously, though, when I first discovered this show, it had the best production values of any show I'd ever seen. The characters captured my interest from the very first minute. I never got bored.
My So-Called Life
Especially in the earlier episodes, the characters and situations were so realistic that I couldn't look away. I love the way each episode is structured around a theme and the way each episode explores POV by repeating the same piece of dialogue in different settings and from different characters. It feels sort of like watching a sestina on the TV. Oh yeah, and Jordan was hot.
Gilmore Girls
The dialogue was to-die-for. 'Nuff said.
The Cosby Show
This one always made me laugh. Plus, I had a crush on the older brother. In the later years, I really liked to watch the cute little granddaughter.
Get Smart
I loved the shoe phone and all of the other gadgets.
Hercules, Xena, and Young Hercules
I lump these into one since they had so much crossover action and I loved the silly campiness of these shows. The hotness factor was also way up there.
Dawson's Creek
It was about young people who knew how to string together sentences. I admired that.
That 70s Show
Red, Fez, Kelso, and Jackie cracked me up.
Lonesome Dove
I don't know why I loved it; I just did. Maybe it's because it was based on the premise that my favorite character from the books didn't die. In the books, Newt's father gives him his horse instead of his name and then leaves him in charge of the ranch. Shortly thereafter, the horse kills Newt. In the show, the dad gives him his horse AND his name and Newt goes out in the world to make the name mean something. The fact that he lives makes me very happy. Also, some of my favorite lines ever come from this show.
Some of these shows, like The Cosby Show or reruns of Get Smart, I watched and adored when I was a kid. Most of these shows, however, I didn't discover until after they were in reruns or off the air completely. I really need to start watching TV that is current.