I'm going to go with the most random thing I can think of and say:

Toei Spider-Man.

It's old and different (very different), it's fully subbed and free to view on Marvel's website, I can guarantee most of the community hasn't seen it, and it has 70's cat drugs.

EDIT: Needs more support...I know, trailer!

http://www.youtube.com/watch?v=3MxGtH-2duM

As pointed out it's a bit too recent/ Since Kyoryuger is running it's not eligible anyway so that would mean the 3 most recent sentai are Goseiger, Gokaiger, and Go-buster. Sorry, I love Goseiger too :(

I have fond memories of Ryukendo, since they actually aired that show here (in the worst schedule possible but it's something).
Good times :)

I say Blade

This may seem like a shot in the dark, but what about the first Power Rangers? Since tokusatu has grown since those early days perhaps taking a look back can tell us more about what has changed and what has stayed the same since those 90s days.

Oh... I just thought that since you already did W which ran along Goseiger that it would be eligible... I don't know who to blame so I'll just blame Decade... ONORE DECADEO!

I'd watch that.
MMPR1, Gransazer, Dairanger, all choices I'd go with.

Does the other "Gosei" series count? both have oddly similar elements right down to Mei being an pink-clad air elemental that commands a phoenix.

The 3 year rule didn't exist when they did W... I think.

I have to say I'm glad a rule finally came down about shows within the past three years. Getting recent Toku into the mix kinda defeats the purpose of LWW. Anyway, my nomination shall be what is has been the last two times, Kamen Rider Black.

Already did Dairanger my friend
This.

And guys please please please keep it to one nomination. We are only accepting one nomination per person for this so please don't change yours after the fact either. Pick one please :)