I had a few over the years, and they stand out in my mind because they were so rare. They were all high school teachers. None of my elementary school teachers or junior high teachers stand out for any but negative reasons.
The human physiology teacher, because he made the lessons fun and interesting with unique turns of phrase to help us remember the various organ functions.
The ancient history teacher, because he made history come alive instead of being dry and boring reading. Because of him, I have a lifelong interest in Ancient Egypt.
Finally, my advanced composition teacher because he came up with interesting choices about which to write, and also held a laid-back classroom atmosphere in which learning was fun. "Cookie, anyone?" and he'd toss a cookie across the room to anyone who raised their hand.