Stargate SG-1 (Syfy, Syndicated)

The basic premise of STARGATE SG-1 is that a secret military team has discovered a network of portals that can instantly transport people all over the galaxy -- so, with typically earnest human curiosity, they set off to discover the mysteries of the cosmos. The show has a very complex mythology: The Stargates were created by the Ancients, an ultra-advanced race that disappeared eons ago, and humans and several other races are slowly figuring out how to use them. One of these is the Goa'uld, a snake-like species of parasites bent on taking over the galaxy; until the Stargate team arrived on the scene to oppose them, they were close to attaining their goal. Richard Dean Anderson (aka MacGyver) starred as Major General Jack O'Neill from 1997-2005; other key personnel include chief researcher Daniel Jackson (Michael Shanks), Lt. Col. Samantha Carter (Amanda Tapping), Lt. Colonel Cameron Mitchell (Ben Browder), and Teal'c (Christopher Judge).

Part of the show's appeal is that the potential of the Stargate portals is virtually limitless -- the gate is wide open for the team to find just about anything on a new world, and they often do. (The equally popular spin-off show, Stargate Atlantis, revealed that the fabled lost city was built on Earth by the Ancients and transported long ago to a distant galaxy, a concept that's equally full of exciting potential storylines.) This never-ending potential makes the show rather addicting, though new viewers may require several episodes to figure out what's going on.

All of that said, Stargate SG-1 is still a fairly conventional TV space opera. The heroes are plucky, the evil villains are rather one-dimensional in their quest for galactic domination, and the crisis du jour is almost always neatly wrapped up before the top of the hour.