20. "Winter Is Coming" (Season 1, Episode 1)
Here's where it all begins. From the opening image of the Wall to the closing shot of Bran Stark's fall, Game of Thrones' premiere episode confidently created the world we'd be inhabiting for five seasons and counting. Getting there wasn't always pretty: The sprawling cast and complex fantasy setting required a heaping helping of exposition, while an earlier version of the pilot was replaced and reshot with a new director, new costumes, and even new cast members. But strong performances by Sean Bean as noble Eddard "Ned" Stark, Mark Addy as blustery King Robert Baratheon, and Emilia Clarke as tormented Daenerys Targaryen proved from the start that this Game would be worth playing.