Here are more recommendations. I didn't include these before because I thought they'd be less likely to appeal to luvmyfirefly, based on what she said. Again, * indicates the show is still airing.
Animation
*The Simpsons: It's a bastion of pop culture references, so good to watch solely for that reason. Lots of people think it's gone downhill over the years, but I think it's still good.
*South Park: The gross out humor might be a turnoff, but despite its appearance, it's quite witty and intelligent, though the arguments of a few episodes I quibble with.
*Futurama: By the same folks who did The Simpsons. A lot of people say they like Futurama better than The Simpsons. It does have continuity that The Simpsons doesn't and a plethora of sci fi references. I happen to like The Simpsons better, but this one's still good, especially if you're a sci-fi fan.
*Family Guy: On the surface this seems a lot like The Simpsons, down to suburban family with an oafish dad, long suffering mom, three kids, and a dog. But the humor is quite different (more direct and quite surreal at times). Also the dog Brian and baby Stewie are the smartest members of the family and don't mind telling you so.
X-Men: This is what I associate most closely with the X-Men franchise. From what I understand, it has a lot of significance to other X-Men fans as well.
Batman: Again, most of my knowledge of the batman world comes from here. I think this is also well regarded by fans. The artwork on this show was very interesting, with dark blues and blacks contrasting with bright oranges and yellows. The intro sequence is also very cool.
Animaniacs: Quick and witty; it's the source of a lot of favorite catch phrases of mine (boingy boingy!) It actually has a lot that is directed towards adults as well as general inanity that entertains both kids and kids at heart. The show did some great parodies; the one of Apocalypse Now (which I found funny before I saw the movie and even funnier afterwards) sticks out most in my mind.
Muppet Babies: The premise of this show is that the muppets are all babies who live in a nursery and are looked after by Nanny. They have lots of adventures using their imaginations (so the POV shifts back and forth between the nursery and their imaginations) and sometimes they sing songs. I have a lot of nostalgic fondness for this show, which is a large part of the appeal for me, but it's also got a lot of clever pop culture references. This show is not syndicated to my knowledge, and will probably never be released on DVD because of the sheer amount of rights that would need to be procured (clips from numerous movies are inserted into the show), but there are ways *cough* youtube *cough* to watch.
Medical Dramas
*ER: It's um, about an ER. based on my experience in ERs, this seems pretty accurate, only exaggerated for dramatic effect.
*Grey's Anatomy: About the lives of surgical residents as they progress through their training. Way too much soap opera at times, but there's also some good stuff about life as a doctor and hospital dynamics and so forth.
*House M.D.: About diagnostic medicine. I've posted in depth my feelings about this show in the show thread, but it's worth watching for the fascinating character study of the title character (who exemplifies some of the best and worst qualities of doctors).
*Nip/Tuck: About plastic surgery. The show does a good job of exploring the specialty and it's accompanying ethical dilemmas, but sometimes the show turns into soft porn (I'm a doctor! You're a patient! It's completely inappropriate, but let's have sex!). Not that there's anything wrong with that.
Sci Mega Franchises:
If you're a sci-fi fan, these are worth seeing just for the sake of seeing them and knowing what everyone else is talking about.
Star Trek: Enterprise, The Original Series, The Next Generation, Deep Space Nine, Voyager: At its core, the Star Trek franchise gives hope by depicting a positive version of the future where human kind has survived and gotten past the plethora social, political, economic, and environmental problems we face today, while also providing a venue to explore these problems through metaphor. It has its ups and downs but its definitely more than spaceships, aliens, and ray guns.
*Doctor Who and Torchwood: Doctor Who worth watching, if only to discover how it's possible for a non soap opera fictional tv show to last 40+ years. Torchwood has John Barrowman/Captain Jack, who is one of those actors/characters who possess that unique intensity which is fascinating to watch. Like the Star Trek franchise, both shows have got their ups and downs, and I'm not as in to them as a lot of other people, but when they're brilliant, they're incredibly so.
The X Files: Despite my overwhelming preference for serial tv, the X Files is one show where I wish they had kept it primarily stand alone procedural episodes. The stand alone episodes, particularly in the early seasons remain my favorites, but the rest is worth watching if only to watch pretty people run around in trenchcoats.
*Stargate: SG1 and SGA: This franchise borrows the idea of "the gods were really aliens" from Chariots of the Gods and there are star gates throughout the universe which act as programmable worm holes that allow instantaneous planet to planet travel. Of course it's a lot more complicated than that. Parts of the franchise are good and parts are weak, but the creators are willing to poke fun at the weaknesses, making itworthwhile in the end.
If you love Pusing Daisies:
Dead Like Me: About the life of Grim Reapers, which is pretty much like life before death. A lot of fun, dark humor, as well as some poignant exploration of life and death (my mom found some parts of it a little hard to watch, actually). Also has my boy Mandy Patinkin.
Wonderfalls: Exploration of 20 something angst and existentialism. A little rough around the edges, but far better than the treatment it got when it was airing.
Comedy/Sitcom
Seinfeld: Necessary to watch if only because it's so firmly engrained in our pop culture. Most episodes involve mean people doing horrible things, which can get tedious if you're not in the mood, but when it's on, it's great.
*The Office (US): Humorous depiction of white collar office drudgery. Often hysterical, though sometimes too painfully awkward to watch directly. The mockumentary style was inspired. This is of course, based on the UK version, which doesn't appeal to me as much.
Serial Drama
*Desperate Housewives: Depiction of Betty Friedan's "The Problem That Has No Name" in a tragi-comical way.
The West Wing: A political drama about life and work in the White House in a somewhat idealistic way.
Six Feet Under: About a dysfunctional family who runs a funeral home. Created by Alan Ball who did American Beauty and my absolute favorite show ever.
The Sopranos: About life in the mafia and other family dramas. This is a truly excellent show all around, but I found that I didn't enjoy it as much as I thought I should.
Sci-Fi/Fantasy/Genre
*Kyle XY: A mysterious boy (Kyle) is discovered in the woods and adopted by a local family. The show essentially is about Kyle trying to find his origins as well as learn about humanity. This one is mostly family drama, with sci-fi elements intruding. The family drama elements impressively manage to be light and heartwarming rather than sacharine. Kyle's discovery of humanity reminds me a lot of Michael Valentine of A Stranger in a Strange Land.
*Robin Hood: A retelling of the Robin Hood legend. Rip roaring action adventure and very entertaining.
*Smallville: A retelling of the Superman story. A lot of it is supercheesy and some of the acting and writing is really bad, but when it's good it's fantastic. Lex's progression into villiany is easily the best part of the show and I personally find it worthwhile watching for that alone. Also, there's lots and lots of HoYay, for those who are in to that thing. And it doesn't really hit it's stride till about halfway in the first season, FYI.
Alias: About spies who run around in various disguises and carry out missions that involve highly implausible stunts. Aside from the popcorn fun, there's a lot of more serious (family) drama to enjoy. The acting from the older generation of actors, Victor Garber, Ron Rifkin, Lena Olin among others, is stellar, while the younger ones hold their own. The show is heavily serialized, so this is definitely a show that's best to start from the very beginning.
The Dead Zone: Based on the Stephen King novel. A man ends up in a coma for 6 years and when he wakes up, he not only discovers that the world has moved on without him but also that he now has psychic powers. Stars Anthony Michael Hall in an impressive comeback.
Jeremiah: Post apocalyptic fiction. A plague wipes out everyone but the children who haven't hit puberty yet. Years later, these kids, now adults, start to pick up the pieces of the old world and start trying to build a new one. A good show for playing Canadian Actor Bingo.
The Twilight Zone: Anthology show that shows that sci-fi relies on excellent writing not special effects. Another show that has worked its way indelibly into our collective consciousness.
Misc
*Ice Road Truckers: If you're interested in isolation and confinement like me, or if you have an inordinate interest in trucking or artic winters you may like this one. The narration is really annoying and repetitive, but you learn to tune that out.
Monty Python's Flying Circus: Variety comedy sketch show. Either Monty Python appeals to you or it doesn't, but so many of the skits have become part of pop culture that its worthwhile to watch and see what everyone else is talking about.
Touching Evil (US): About a cop who has suffered frontal lobe injury. Fantastic character study, starring Jeffrey Donovan (now on Burn Notice) who took his role very seriously. Fascinating to watch, especially if you are familiar with Phineas Gage (classic psychology case study who suffered serious frontal lobe injury and exhibited drastic behavioral changes after his injury and contributed to the understanding of the frontal lobe's role in "higher brain functions" like decision making and inhibition).
