I like Mike better I think, but mostly because by then they had the format down pat and Mike was the head writer for a lot of Joel's episodes anyway. Not to take anything away from Joel - the guy created the show and some of my favorite episodes are his. The last three seasons of the show are much better than the rest though I think.

I'll have to look over my list when I get home from work, but ones that immediately come to mind are "Mitchell", "Prince of Space", "Santa Clause Conquers the Martians", "The Incredibly Strange People Who Stopped Living and Became Mixed-Up Zombies", and the one with the wannabe James Bond guy (can't remember the title right now). Also, the first 10 minutes of "Teenagers From Outer Space" is gold.