The only couple I have ever been a fan of due to their extreme chemistry is Chuck and Blair. I have always love them pre-Chair and all, but these two together are unbelievable. Til now my favorite GG scene has to be the Limo Scene. That was utterly epic, and it did it for me. And my second, third, fourth, fifth and so forth favorite scenes are still of Chair with or without other characters, so there is really no point to even consider a second and thrid place couple because they to me are not even a fraction of what Chair is. They are so disfunctional, yet it is so natural.
Chuck and Blair are the best couple ever and I know they will stay that way.