I was a huge Jason fan and had quite a bit of disdain for Tommy when he took over, but as the show went on, he started growing on me, so now I like both of them equally. ^_^
The series started hitting its stride around the time that Lord Zedd came around imo. That's when they stopped using footage from the original Super Sentai whateverthefuckitwas series spliced into the show. The very first season of Power Rangers was horrible in this aspect. It was extremely disjointed with some of the worst non-seamless editing ever. Check out the first episode.
http://www.youtube.com/watch?v=Q7TkrB8Q5P0
http://www.youtube.com/watch?v=CN7hrnlhxxI&feature=related
When the Lord Zedd arc started, things were still cheesy but at least it seemed like the vision was a bit more in control. It seemed the producers and cast knew that the show was already marked as cheesy, so it seems they went along with it, and seemed to have fun. As a result, it came off far more enjoyable, even if the fight scenes weren't nearly as cool as the Japanese versions.