Reddit reviews Super Sentai Zyuranger

I'm not particularly qualified to say which of the middle seasons you should and shouldn't watch, but the run from Mighty Morphin' through In Space is a classic. You could probably pick up at the start of In Space without much trouble, to be honest. From there, Time Force and RPM have probably the best reputations, but it depends on taste - there's any number of "best season" threads you could check out here for more in-depth responses.

Sentai does have a generally better reputation - there are better and worse seasons, but for the most part it's just easier to make a good show when you're making it all from scratch than when you're retro-fitting half of it around existing footage, you know? There's no US subbed releases of it on DVD/Blu-Ray^note , although it's possible that Japanese releases have English subs - someone else would have to confirm that.

^note Zyuranger - which became the first season of Mighty Morphin' - is getting a complete series release in February.

Required watching:

Power Rangers

Time Force, SPD, Mystic Force

Super Sentai

Dekaranger, Magiranger, Shinkenger, Go-Busters, and Kyoryuger.

As for skipping, I can't really think of anything at the current moment, but I'm sure if you were to give me a few days, I could easily find a few series to skip over.

Sentai? I'm a toku nut, and the 'fan boy' inside of me would tell you to skip over the current PR product (because the acting is terribad, and Saban merged series in Megaforce and Super Megaforce) (Goseiger was Megaforce, and Gokaiger was Super Megaforce), but I'm not here to cause problems.

As for picking up subtitled versions, the only one that is getting a DVD release RIGHT NOW would be Zyuranger, which we faithfully know as MMPR Season 1. Everything else you'll have to look towards fansub groups like Over-Time, TV-N, G.U.I.S. and other groups. I would be suggesting KRDL as a start to finding out which groups did what series, but sadly it seems as though the servers are no longer online, so you'll need to do a bit of hunting on your own.

Hopefully this gives you a good start. Also, I would suggest Gokaiger and Goseiger IF you want to fill in the plot lines that Megaforce and Super Megaforce left out.

You're welcome. Here's two more I forgot.

Zyuranger Preorder on Amazon

These guys subbed Abaranger which was adapted as Dino Thunder

They shouldn't be.

The DVDs have been out for a while now

Same for Zyuuranger

Here is the mobile version of your link

http://www.amazon.com/Super-Sentai-Zyuranger-Yuuta-Mochizuki/dp/B00P9UVC0I/ref=sr_1_1?ie=UTF8&qid=1425497658&sr=8-1&keywords=zyuranger

No problem, and if you'd like to give the source material a watch one day, they're starting to release them on DVD in America. Here's Zyuranger as an example: https://www.amazon.com/Super-Sentai-Zyuranger-Yuuta-Mochizuki/dp/B00P9UVC0I/

Now confirmed to be on Amazon.ca, as seen here: http://www.amazon.ca/Power-Rangers-Sentai-Zyuranger-Complete/dp/B00P9UVC0I/ref=sr_1_2?ie=UTF8&qid=1416019379&sr=8-2&keywords=zyuranger

Having played it, it feels more based off the original Super Sentail shows than the Power Rangers adaptation, though it has some nods to that version too. Maybe I just see that because I'm more a fan of the original shows, though(and happy that they're finally getting official US DVD releases.