Considering the general quality of Toku songs, this are VERY HARD choices.

Super Sentai:
Almost all their songs have been great. I'll go with Samurai Sentai Shinkenger, since it managed to electrify me into loving Sentai all by itself.

http://www.youtube.com/watch?v=IBRwE_ynQgA

Kamen Rider:
Likewise, W-B-X from Kamen Rider W made me fall in love with Kamen Rider.

http://www.youtube.com/watch?v=HBp2i4HL6WI

I'll admit it, Comic, Shinkenger does have a very good opener.

http://www.youtube.com/watch?v=H_EmYshGJdI

Chan Chanbara! Chanbara!

I tend to favor what I'm watching at the moment, and right now that's the opening to Fourze, also the opening and end to Akibaranger

To pick just one in the "other" category would be impossible. So I won't.

http://www.youtube.com/watch?v=nybqhMbWTOI

http://www.youtube.com/watch?v=WmmfwPVB2yw

http://www.youtube.com/watch?v=Gp0QI4izptw

http://www.youtube.com/watch?v=zEDSDYrtksE

OOO's Anything Goes.
Ear Wormed me so hard that I couldn't accept anything other.

Super Sentai: http://www.youtube.com/watch?v=hEOr9EtqxiM

Kamen Rider: http://www.youtube.com/watch?v=Tw4eK6CNwLA

Metal Hero: http://www.youtube.com/watch?v=X26_t6VoyeQ]

Ultra Series: http://www.youtube.com/watch?v=FaXzYBAjN9s

Others: http://www.youtube.com/watch?v=Bb2GvYmaUok

Sentai: Tie between gokaiger and go-busters
Kamen rider: switch on and anything goes
Metal heroes: Gavan
Other:Madan Senki Ryukendo

Mild adjustment to my original answer:
The MMPR Theme.

Sentai:
Gokaiger

http://www.youtube.com/watch?v=x_Wd2y_Mlbs

Kamen Rider:
Joruney through the decade-Gackt
http://www.youtube.com/watch?v=jcu9ZzRCn90

Other:
GARO JAM Project
http://www.youtube.com/watch?v=qV2a4YVJV7M

I would say probably Break the Chain from Kiva, followed by the DaiRanger theme and then the very first Garo theme (the opening from the first 13 episodes).