Archive Panic: With just under 1730 episodes plus movies (not included) (as of the start of Gokaiger) and 47-51 more added each year, it's going to take quite a long time to watch them all.
Depending on how long each show is (whether commercials count, theme song, credits) it could take anywhere from 24 days (20 min/episode) to over a month (36 days and 56 minutes at 30 min/episode) if watched continually without stopping. Both numbers use 1730 episodes stated above (still not including movies).
The 1800th episode mark has already hit in episode 21 of Go-Busters (aired last July 15).
However, all of this is eased somewhat by the fact that (with a fewnotableexceptions) each series in the franchise has a self-contained narrative with separate casts, with almost no connections to any of the other series, allowing you to watch them freely in any order without missing a thing.
The 2000th episode was episode 29 of Zyuohger in addition to that it was a crossover with Gokaiger.
Base-Breaking Character: With a franchise this long-lasting, it's inevitable that some of the characters would be controversial. Many Rangers are considered as "mixed bags" by the fanbase for one reason or another. Be it for their excess of energy (Yosuke, Ban, Kai, Jan, Sosuke), their excess of cuteness (Saki), having an inadequate behavior (Kou), being too sensitive (Alata, Right, Misao), being truly dumb (Natsuki), lacking personality (Hiromu, Souji), being obnoxious (Takaharu), or being a spotlight hogger (Daigo Kiryu, Lucky). On the other hand, they have at least either fans or people that tolerate them.
The Super Sentai fanbase enjoys a close relationship with fans of Kamen Rider, mostly due to being sister series but also for having different, yet equally valid directions for the henshin hero and toku genre.
Surprisingly, they also get along well with the Power Rangers fans despite the whole possible regional adaptation arguments. This even extends to Japan where some fans enjoy a Power Rangers season just as much or even more than their original counterpart.
Growing the Beard: Notably had a four season period of this, beginning with Changeman (first season with a successfully dark plot, as well as having better writing) and ending with Liveman (introduced series traditions such as a Three Plus Two format, two already combined robots combining, and a female blue ranger). In addition, the two seasons in between, Flashman and Maskman, were very well received.