He-Man revitalizes my spirit when I watch. I'll continue watching forever. I also recomend it to all the children and young at heart I meet.
My favourite episode of all time would have to be 1-18 The Creatures From The Tar Swamp. It was the one I remembered best from my youth. I'm not sure why it just "stuck" there.
This show teaches as well as entertains the watchers. It always leaves you with a message of goodness, which in my opinion can be so hard to find in cartoons today. Do yourself a favour, start watching again, or watch it for the first time. You will be glad you did.