TV Show: Firefly - best show in a long time that got tragically cut short
I love you.
ANYways, I'm going to avoid "favourite movies" because the topic just seems to give me headaches, but I'll take a stab at TV shows.
Buffy the Vampire Slayer: Might be old and dead now, but overall I'd still say it's likely to be one of my favourite shows of all-time. I'll need to do another marathon of it sometime this summer...
Angel: Same Whedon humor as Buffy, darker themes, a great cast, and some great plots. I want to stab Conner relentlessly, but Angel was a great show and I still love rewatching it.
Firefly: Because I'm on a Whedon-roll here, and the cancellation of Firefly puts me into genocidal rages. A show so great cut short for ridiculous reasons... Even if it is a handful of episodes and a single movie (for now), it was awesome, had awesome plots and great characters, and I love it to bits.
Xena: Warrior Princess: I /have/ to include Xena XD I might not love it as much as some other series, but I'd definitely rewatch it again if given the chance (which is very possible since we own it all on DVD). Many good times with that series...
Dark Angel: I really loved this one, too, even if the way it was finished off left much to be desired (can't really blame them for it, though - the second season just had so much potential). Great plots, interesting characters, and a bit of that Buffy-flare I love with series'. It was great while it lasted.
I think that covers the top of the top for me and live-action TV shows (though I certainly have many more I could list)... I think I'll skip cartoons and Anime here because there's just far too many to list. Of RECENT favorites, though, I would definitely include
Avatar: The Last Airbender. I just can't get enough of that series.