SG-1 and Atlantis are really, really excellent sci-fi shows. They're very tongue in cheek and self referential (the first episode of SG-1 featuring Richard Dean Anderson, who played MacGyver, used the term "MacGyvering", and then did a cut away to him for comedic effect). They're just very fun shows that any Sci-Fi nerd would love, given the chance.
Also, DS9 is a very underrated Star Trek. It didn't hit its stride until they got the Defiant, and a lot of people had given up on the show by then... Great cast of characters... Garak was one of the better characters in the entire Star Trek series of shows...
Those are just some of my favourites, and all quality shows for anyone to watch... You can read the synopses and discover the genres yourself..
Also, here's a bonus fun show that most people have probably forgotten: The Adventures of Brisco County Jr.