If I had to choose my favorite on-screen couple (disregarding anime or asian dramas, of course) it would be Anne Shirley and Gilbert Blythe from the 86/87/00 adaptation of Anne of Green Gables. (Which also happens to be my favorite book and movie as well). Go figure! ^_^
I apologize for the crappiness of the clips... the DVD boxset I ordered hasn't come yet, and I couldn't wait for it, so I had to use various clips off youtube. But somethings better than nothing, ne? ;)