[Matrixbeast]

Gekiranger.
Looking back on it, the entire series was my favorite moment (And because it's no longer limited to moments in 2012, I can now gush more ). Very rarely does a series enthrall me so well that I can't stop marathoning it. The character of Jan began as the stereotypical jungle boy in modern day, but he grows, and while his "Nikiniki wazawaza" doesn't quite disappear, his demeanor and attitude grow for the better, but he also never loses that million dollar smile. Ran and Retsu didn't have much to do, both being the straight man to the rest of the cast, but they both had enough to them that made them memorable characters (Ran's being the leader, Retsu just being one of the best characters to watch whenever he gets focus), Gou is the definition of badass. And Ken. Yeah, he was there too.
I could gush on and on about Rio and Mele, so I'll try to be brief. Rio and Mele are the kinds of villains I want to see more of. The villains who are actual characters in and of themselves. They have story arcs, they have emotions beyond "GRRAR MY MONSTER DIED LET ME SCREAM FOR THE NEXT 5 MINUTES!", they were absolutely perfect (Though Mele's fangirling over Rio did get a little old 40 episodes in), and I long to see Sentai create villains and characters like them again.

The suits did take some time for them to grow on me, but after they did, I loved them. Slim and sleek to invoke fluidity, exactly what a martial arts series should do. GekiTouja wasn't the best mecha, but I grew to enjoy the commentated fights, too.

Gekiranger managed to do everything right, in my eyes. Placing emphasis on story, while keeping the fights stylish and enjoyable to watch, making the villains actual characters, and just being a great experience.
Too many Sentai recommendations are based almost entirely on "The suits and mecha look cool." And it too Gekiranger to show me that not all Sentai are Style over Substance.