Your Favorite Anime theme song

[Amenta Kaiser]

Just Communication for Gundam Wing.

 

[sam_savage1393]

I don't know why, but the Simpson's theme song is the only one I can think of at the moment that I enjoy..

 

[Space Spoons]

This is a tough one. I guess my favorite opening would have to be "Kao Deka-i" from the 1998 Dr. Slump remake.

Spoiler: Kao Deka-i

Apart from being a really catchy song, it's just ridiculously high-energy and it fits so well with the weird "what the hell's going on" mood of the anime itself.

My favorite closing is easily "Detekoi Tobikiri Zenkai Power", the first closing from Dragon Ball Z.

Spoiler: Detekoi Tobikiri Zenkai Power

I have a lot of fondness for this closing not only because DBZ was my first real experience with anime, but also because it's highly reflective of the mood DBZ had prior to the Freiza Saga. The fighters were stronger, and the threats were a bit more serious, but in tone, it was still really just an extension of the original Dragon Ball.

 

[CrazyGirl17]

Mine include (both openings and closings):
The Original Pokemon theme (even now, I can still recall the words)
"Resonance" from Soul Eater
"Haruka Kanata" and "Go" from Naruto
"Hemisphere" from RahXephon
"*Asterisk* and "DTechno Life"- from Bleach
"Uninstall" from Bokurano
"Smile Bomb"- from Yu Yu Hakusho
"Makkai No Chikkai"- from Buso Renkin
and
"Houkuboshi"- from Black Cat
"Loop"- from Tsubasa: Resvoir Chronicles
"Hoshikari"- from Bleach

 

[Vet2501]

Rise by Yokko Kanno The opening from Ghost in the Shell SAC 2nd GIG

 

[C117]

The intro theme of Shikabane Hime is pretty good...

 

[Aura Guardian]

Spoiler: This one

 

[PedroSteckecilo]

Probably a toss up between these four...

Tank from Cowboy Bebop
Guns & Roses from Baccano
Sakura from Eureka 7 (Opening 4)
Rewrite from Full Metal Alchemist (Opening 4)

 

[Thegoodfriar]

Cowboy Beebop's, Samurai Shamploo, and Afro Samurai all have great intros.

But my personal favorite is the opening to Claymore by Nightmare.

 

[Rock 'n' Soul]

Spoiler

 

[Pingieking]

Opening to Mushishi (goes very well with the anime's emotional state): http://www.youtube.com/watch?v=ZnQrE_eWpco

Opening to Last Exile (some nice techno): http://www.youtube.com/watch?v=y4gMfFOnzd4

Opening to Gantz (Asian rap is awesome): http://www.youtube.com/watch?v=QFfbjHygQNs

Opening to Lucky Star (there' no way not to love this song): http://www.youtube.com/watch?v=ieQ1rAIjzXc

Some others that people have already stated. Such as the Trigun opening, Death Note opening and closing, Exel Saga opening.
EDIT: And I forgot about the Haruhi Suzumiya closing. That thing is on the same level as the Lucky Star opening. Videos fixed (sort of).

This one isn't a theme, but I love it for it's sheer hilarity and awesomeness for cell phone ring tones. It's the Purupuru Pururin Rin song from Welcome To The NHK: http://www.youtube.com/watch?v=l7asrTH3gII

 

[[Kira Must Die]]

The second opening and ending themes to Death Note.

 

[John Funk]

"Innocent Starter." Magical Girl Lyrical Nanoha season one opening. Partly because I liked it immediately. Partly because I loved it more halfway through the season, when the lyrics actually started to make sense.

You like Innocent Starter more than Eternal Blaze (the opening to A's)? Huh.

 

[NeutralDrow]

"Innocent Starter." Magical Girl Lyrical Nanoha season one opening. Partly because I liked it immediately. Partly because I loved it more halfway through the season, when the lyrics actually started to make sense.

You like Innocent Starter more than Eternal Blaze (the opening to A's)? Huh.

Hard choice, of course, but so far Eternal Blaze hasn't gripped me as much as Innocent Starter...'cept the opening animation, of course, A's is much cooler in that regard. I like the first one a lot because it's a good song, and because it described the Nanoha/Fate dynamic (my favorite part of the show) so well. I'm only five episodes into A's so far, so that might change.

...come to think of it, I also like "Make a Little Wish" more than "Spiritual Garden," but I think that might be simply because of the first season's last episode.

 

[Julianking93]

Tie between these two:

 

[X Gintoki X]

"libera me" from hell ~ Tengan toppa
number one by hazel Fernandes preferably the violin version
modern strange cowboy by Granrodeo from needless
all of the openings for gintama but especially Donten by DOES
also rather fond of bakusou yumeuta by Diggy-MO' from Soul Eater

 

[GloatingSwine]

"Innocent Starter." Magical Girl Lyrical Nanoha season one opening. Partly because I liked it immediately. Partly because I loved it more halfway through the season, when the lyrics actually started to make sense.

You like Innocent Starter more than Eternal Blaze (the opening to A's)? Huh.

That's the only Nanoha intro I need.

/prefers Secret Ambition anyway.

 

[Eldarion]

Cruel Angel's Thesis

 

[Sethzard]

Code geass R2 opening 1 (02 by orange range)