Posted on: 02/17/21 12:24AM
Samurai Sentai Shinkenger is my personal favorite and it has the bonus of being the first Super Sentai series to crossover with a Kamen Rider series, so it could help you get into that franchise as well. The possible downside is, that Kamen Rider series was Decade, but who knows, you may end up liking it. Actual downsides are the mecha designs, which are kind of ugly, as are the suits, but the plot more than makes up for it.
But I think a good place to jump into would be Tokumei Sentai Go-Busters. It has a number of references to Power Rangers, such as the giant enemy robots being termed as MegaZords and each one being >thing<Zord, their transformation items are called the Morphin Brace and Morphin Blaster, both of which announce "It's Morphin' Time!" and they also have a Powered Custom power up that acts as a sort of Battlizer. If you like the idea of having a robot as a friend, then you'll love the Buddy Roids.
If you really want to start out with the first series to be adapted into Power Rangers, then there's Kyōryū Sentai Zyuranger, which is a series I adore. Witch Bandora (Rita in PR) and her gang are an amazing bunch with personality and they almost feel sort of like a family, unlike in PR, where Rita just yells and everybody is an idiot. Grifforzer, who became Goldar, has an actual personality beyond being a loudmouth braggart who blames his defeats on the Rangers and Lami, who became Scorpina shows up a whole lot more and has an actual personality other than "evil lady that kinda shows up now and again and becomes a freaky monster". Burai, the DragonRager (AKA green Ranger) isn't just a bad guy because of brainwashing through magic. The mecha are also sentient, capable of talking and expressing emotions.
Sure, there's no Bulk and Skull equivalent in Zyuranger, but... well, can't have everything.
And if you're really into trains and the theme of IMAGINATION, then there's always Ressha Sentai ToQger. The bad guys, I find, were way more interested than the good guys, especially Emperor of Darkness Z.