Basically, anything made in the 80s/early 90s
My absolute favourite show as a kid - The Animals Of Farthing Wood:
Don't you open that TRAPDOOR! :
Round The Twist:
Poddington Peas: catchy (as proven by the CF Christmas meet when everyone started randomly singing it)
Family Ness:
Duckula:
Inspector Gadget:
Rescue Rangers:
Ducktales (awoo ohhh):
Danger Mouse:
And, of course, the best of them all - Knightmare:
Edit: It doesn't specifically say TV themes so I'm adding this. It's the song to my all time favourite animated film (hell, possibly my all time favourite film):