Broken Meeple Top 10 - Essential Expansions

I love board game expansions. Whenever they come out, I'm always interested in them.........well it depends. More of the same is all well and good but you reach a limit of how much you need. Some expansions though, change the original so much for the better that it makes it so much more enjoyable. Sometimes to the point where I won't even play the original base version any more.
Which expansions do I feel are essential for any lover of the original game to get? Which are yours, leave them in the comments below!