Power Rangers jumped the shark with the White Ranger, as far as I'm concerned. The first season or two of Power Rangers was fine, but it cannot compare to the epic awesomeness of Galaxy Rangers.
Power Rangers was fine up until about the fifth season. Then they killed Zordon (the giant head in a tube), and started changing the cast every season. They did kinda go overkill with the Tommy character, having him be the Green, White, Red, and Black ranger at various points over the past 15 years.
I never saw this
Galaxy Rangers show. Is it still on tv anywhere?