Here were some reasons why I considered MMPR's fun to watch moments:
The possible chemistry of Jason and Trini. Somehow, although Trini at times would drive her teammates crazy with her aggressiveness, she and Jason seemed to have a chemistry. Too bad though, Austin St. John left for some reason unknown while Thuy Trang had salary disputes with Saban during season two, had enough and quit.
Bulk and Skull- Idiots help make the world go round. Too bad though, they don't have superpowers. I admit I didn't like Skull because he was going after Kimberly and glad that it ended. :-P Of course, campy humor is good. But I admit, MMPR isn't as funny as Go-onger and Carranger IMO.
Tommy and Kimberly- I really continued watching MMPR because of these two and I loved their relationship. Too bad Amy Jo Johnson left the set and later in Zeo, the writers had a stupid dear John letter script rather than keep their long distance relationship, which I might soon write a fan-fic if I really get the time to get them back together. :-P
The relationship of Lord Zedd and Rita as husband and wife in season 2-3. In season two, Lord Zedd started off as a pretty one-sided villain. However when he and Rita Repulsa got married, things started to get rough for the rangers since the two always cooked up schemes that worked better than each one was working alone. Also it meant Lord Zedd was no longer limited to just being a grouchy, brute-force relying monster but also as Rita Repulsa's wonderful husband. Although they never won but the rangers suffered so much stress because of these two. And yup, they've become one of my favorite couples.