[Dr Kain]

This is a hard decision for me. Season 2 gave me my favorite mecha for the series, it gaves us Lord Zedd, and some amazing monster designs (hence why DaiRanger is my favorite Sentai). On the other hand, Zedd got dumb when Rita came in, and Goldar did almost nothing the entire series. Plus, Serpenterra was awesome despite his lack of using Energizers.

Then you have Zeo, which I also enjoyed, thought it had a great finale.

However, I am probalby going to vote for In Space since it featured a full ongoing storyline, featured characters from every previous season, and concluded it all. Plus, Astronema was awesome and serious like Zedd used to be and Darkonda was pretty kick ass. Loved his whole concept. On the other hand, I hated the rangers outside of Andro. They were so annoying and I really wished that tank monster thing had run over Ashley because she was the worst of the bunch.