I'm going to be completely unoriginal and go with something that kicks the nostalgia up a level. DBZ's "Rock the Dragon" opening. It is still one of my favorite openings because for the most part DBZ was all about fights and this got you pumped up to see the episode. I know that dubbed series usually have crap openings like Fulmetal Alchemist Brotherhood has its english dub opening cut from 90 seconds to 30 seconds. However the dbz dub is a staple for fighting fans I think, especially the ones who grew up in the 90s and it was one of their first experiences with anime. There's a few different versons around but I'm talking about the one that starts with Shenron and ends with Goku going SS. It is just full of fight clips set to rock.That Rock the Dragon intro was just awesome. Even now it makes me want to watch the show again.
I like the upbeat ones, although sometimes I'll go for something dark if it's particularly awesome. My favorites include the openings to Ouran High School Host Club, Azumanga Daioh, Lupin The Third, Love Hina and Death Note (either one is good, but the second one is more my favorite of the two)
Fuushigi Yuugi's opening theme. I would watch only for that, because I think the anime was horrible in its portrayal of female friendship and tiresome with everybody trying to get in Miaka's magical virginal knickers.
But the opening theme song was rocking, and had that bygone era music style meshing with it (sort of like Baroque rock, but the far eastern equivalent of...) and it worked really well and it was pretty.
My favorite openings are: Beyond the Boundary, Naruto during the chunin exams, and of course the original opening song for Pokemon. My favorite out of all of those would have to be Naruto's opening during the chunin exams because it always got me pumped to watch an episode.
Tough one. I generally tend to love the OPs of every anime that I like, it's like... No matter how bad I thought the OP was in the beginning, if I start liking the show, I start liking the OP aswell, for some reason. For that reason alone, I feel like saying Clannad... But well, I do feel like the Elfen Lied opening is slightly better than everything else. It's just, perfection.
But since you said songs, plural, then I'll just mention the ones that I really like from the tip of my head.
* Clannad OPs (all of them...)
* Kanon 2006 Opening
* Elfen Lied Opening
* WataMote Opening
* Legend of the Galactic Heroes Opening 2
* Ergo Proxy Opening
* AnoHana Opening
* Lucky Star Opening
And it's funny, I didn't get the chance to see the whole anime, I just watched a few episodes when my roommate watched the show. But somehow the song stuck with me and became my favorite.
My favorite anime songs are from Gundam and YuYu Hakusho. Those two animes got really popular in my country for a while, and although I never watched Gundam myself, I did get to catch its opening theme music a lot of times and I always used to let the intro song finish before I changed the channel whenever I caught it way back when.
I think a little differently than Lix, he said all the Clannad openings, but personally I think Clannad's 2nd opening was the best.
Also all fo Naruto's openings are jsut amazing , but probably out of all of them I would choose, Sign, fighting dreamers, and of course ROCKS, because it was the very first opening for naruto
