Just gonna chime in my 2 cents. Go-Onger was a series I was really skeptical of getting into, sort of like Hibiki for Kamen Rider. However, I went into it with an open mind, and walked out with having a new favorite Sentai. It won't top Gekiranger as my star since Geki was superb in my book, as well as my first not-Shinkenger Sentai. However, Go-Onger was certainly the most fun I had with Sentai. I think it had a nice blend of plot and comedy to make it fairly interesting to watch. The dynamic between the Go-Ongers and their Engines reminded me a lot of Digimon, and that's something I enjoyed a lot too.
I liked almost all the characters, the villains were pretty entertaining, and even at the most zany moments, there was still usually a purpose to it all. The Engines were my favorite part of the show, and the sentience of them all really enhanced the experience to me.
While it's not my #1 Sentai, it's certainly one of my favorites. Having actually watched the show, I definitely don't see the hate.