What makes a teacher memorable?

With the new school year quickly approaching, many teachers are already getting prepared, setting up their classroom, organizing lesson plans etc. And, at the same time, many kids are enjoying their last bit of summer and anxiously awaiting that first day. It's going to be a great year and one to remember.
So, in honor of all the hard-working teachers out there, let's reply with the name of your most memorable teacher. And why not share what made him/her one to remember?!