Wow, best scenes where to start:
West Wing had so many great scenes, this may be my favourite:
Breaking Bad is a hard show to narrow down your favourite scene, but this was was great:
This is the final scene of the last episode of Game of Thrones, another great show that's hard to narrow down a favourite scene. (season 4 episode 10) so spoiler warning.
I'll post more as I think of them.