As cliched as it sounds, Mr.Big from SEX & THE CITY: old-school sexy, good in bed, elegant, a Park Avenue apt., charming, and masculine. There's always Steve from the same show as well.
I'd also add Claire's Republican boyfriend at the end of SIX FEET UNDER because he was interesting and fun to argue with.
Then there's Rob Lowe's gay brother in BROTHERS & SISTERS...look at me, I'm a TV boyfriend whore.
"Some people can thrive and bloom living life in a living room, that's perfect for some people of one hundred and five. But I at least gotta try, when I think of all the sights that I gotta see, all the places I gotta play, all the things that I gotta be at"