How would I have ever said I would never watch Turboranger when I watched that show like 10 years ago?
Saying Fiveman is Soda's best work is not really saying much when Soda's work is pretty mediocre at best. Of the shows I have watched or am currently watching, I actually consider Dynaman to be his best series as it is so energetic and full of life. Also, I'm not bored to death during the mech fights despite them being the same mech battle as every other one of his shows.
As for Fiveman itself, I thought the show started out solid but then fell apart when they began having those stupid plush toys make appearances. Although, I did like the episode where the grunts took command.
Finally, for Megaranger, I can not believe you found it boring. Sure, it is no Dai or Kaku, but the show has a lot going for it with a strong ranger cast that actually feel like teenagers, decent villains, excellent music, and some cool mecha.