not sure what you already watch but a few recomendations are...

brothers & sisters is a good family drama with great characters
smallville is just amazing
one tree hill seasons 1-6
gilmore girls - funny and light hearted
prison break - you'll watch one episode and be hooked, v addictive :)
greys anatomy is good
pretty little liars

Pushing Daisies, The Big Bang Theory, Modern Family, Dead Like Me, Carnivale, Charmed, How I Met Your Mother, Scrubs, and of course LOST.

^^^These are shows most people on Fanpop seem to like. I like a few of them I tried to just list comedy/fantasy since that's what you're looking for. Good luck with your search!

Supernatural - it's a fantasy, funny, dramatic, and action packed.
I noticed you're already a fan of BtVS- I've found that most Buffy fans like Supernatural as well. It has that same great blend of comedy, action and drama. Plus great writing and acting.

I also recommend giving 24 a chance even though it doesn't fit your requirements. It's a unique and intensely entertaining show. Plus we're having a link where you can watch it from the beginning with us starting July 10th!