The Buffy theme... great for practicing octave chords.
The bass from the Alf theme...
Really old ones like the theme from Thunderbirds, the Persuaders or Dr. Who are fun if you can find a midi of em and translate it to guitar. The Simpsons has gotta be the hardest piece to play in the world... those fast runs are unreal.
The theme from Blade Runner done as a dance version, Twister & stuff like the Bond theme or Hawaii five 0.