Presuming it is non-animation and not an episode I watched randomly with a friend, it would be the new Battlestar Galactica series. Like it very much and think it dethroned Babylon 5 as my personal best scifi series ever made (by scifi I mean lots of space, bad SFX and guys in uniforms talking, not some time travel dramas). Favorite characters would be Admiral Adama, Gaius Balthar and Brother Cavil.
