I started on Shinkenger, but Gokaiger got me hooked and now I'm catching up. With the exception of Power Rangers RPM, I feel like the Sentai is either on par or in most cases, vastly superior to the Power Rangers
Ryusoulger is ending. I liked this series. Far better than Kyoryuger in my books. Although Red was the first to get the power-ups, this series did put the other Ryusoulgers in the spotlight. Excluding Ui, there wasn't any characters in that show I disliked. My favorites were Melto, Bamba, and Tyramigo, and that fire mech that liked asking riddles
One thing I wish Sentai would change is their endings. They are by far the best and most intense parts of the series. Sadly they are extremely rushed and ends too quickly but at the same time we have so many filler and unnecessary episodes.