Goggle V's primary weapons were all gymnastics based. Pretty cool really. :) Nobody has thought of using gymnastic weapons for battle.
The Prism weapons in Flashman. I find them unique due to their crystal-like appearances.
The Rolling Vulcan from Flashman. I pretty find this weapon awesome though, perhaps better not replicated. It's imo the best Sentai bazooka ever! All I can say is if I were the monster of the week or Sentai villain, I'd go O_o when I see it in person and see its power!
Jetman's Fire Bazooka was born from a... VEHICLE?! Awesome! I personally thought aside from the drama involved, having your car turn into a cannon in battle is no walk in the park.
Kibaranger's Byakko Shinken. Not only was it carried around while Kou was unmorphed, it could literally talk and give Kou instructions! I thought that Byakko Shinken really beats Saba anytime! I have to say that Byakko Shinken was linked to everything about Kou and that it played a role in his maturity.
Gaorangers' Haja Hyakujuken. Rather than the standard blaster, this one creates a new concept of a sword finisher than a projectile-based one.
The Dual Crusher in Boukenger. I always thought having two modes for a finishing weapon is cool. The cement mixer and the drill head are somewhat complementary to each other.
Shinken Red's Rekka Daizanto is not only that huge, it also converts into a bazooka! :P All I can say is this- hey is it possible to wield a weapon like that with great efficiency if it's already made of steel?!
Shinken Yellow's Land Slicer. It's the LARGEST shuriken I've seen. I admit it looks pretty dangerous like a grass cutter. Wow Kotoha has to be complemented by you people for wielding such weapon without hurting herself!