My favorite openings, in descending order:
--First (*~Asterisk, by Orange Range). Orange Range rocks pretty hard, and this is probably one of their best songs...really mellow, with a good beat. The animation is awesome, too; really reminiscent of the early manga chapter title pages. I seriously watched just the opening like 20 times when I first saw it.
--Third (Ichirin no Hana, by High and Mighty Color). I love how grand the song sounds. That's an odd description for it, I know, but if you think about it, "grand" is a descriptor that really does suit it quite well. The animation was what prevented this from being tied with the first opening; while excellent, there wasn't a whole lot actually happening. Incidentally, it was this opening that got me into High and Mighty Color, which is another excellent band.
--Fourth (Tonight Tonight Tonight, by the Beat Crusaders). Very unique song and animation style, but that's a good thing. The animation reminds me of *~Asterisk's, and I can't wait for the full single to be released. This would be tied with the third opening if not for the fact that it's a filler opening, which bothers me for some reason. I could see this having been used for the upcoming arc based off the manga.
--Second (D-Technolife, by Uverworld). Everybody loves this opening, for some reason. It's actually very standard Shonen: angsty song coupled with action-packed animation showing battles between totally random characters. While that's all well and good, it just didn't feel like Bleach. It wasn't unique enough. That being said, I don't mind Uverworld or their music. I just wish Studio Pierrot hadn't used them for Bleach (on a side note: what kind of name for a song is D-Technolife? What does that MEAN? At least *~Asterisk makes sense--the * is often called "star", and the song is about stars and stuff--but what's a D-Technolife?)
Endings, in descending order:
--Third (Houkiboushi, by Younha). Not only is the approach to the animation REALLY unique, but the song is one of those insanely catchy J-pop tunes. Some Divisions' endings could have been done better (ie, the first Division's), but overall, most had a nice balance between the amusing and the kicka**.
--Eight (Movin'! by Takacha). Groovy beat, mellow song (I like mellow music, by the way), neat animation (Chad with his guitar!) when it isn't Kon being randomly chased by the Modsouls. That's actually the only part of this ending that i don't like.
--First (Life Is Like A Boat, by Rie Fu)/Fifth (Life, by Yui). These two are tied, although I like them for different reasons. The first ending has what may be the only Japanese singer who can actually sing properly in English, and is generally a nice, mellow ending that juxtaposes its accompanying opening quite well. As for the fifth, there's something about the song that makes you want to listen to it more and more. The animation for both is good, but doesn't really stand out (a fact that actually applies to most of the Bleach endings, I've found).
--Second (Thank You!! by Home Made Kazoku)/Seventh (Hanabi by Ikimono-gakari). These were the endings that made me go "meh". They weren't bad, but didn't really stand out to me in any way.
--Fourth (Happy People by Skoop on Somebody)/Sixth (My Pace by SunSet Swish). These were the endings that I didn't like. The fourth, while I don't hate it as much as much of the Bleach fandom seems to, just didn't have a very good song and only had the standard mediocre animation. As for the sixth...the song was weird, and the animation entirely involved Kon and the Modsouls, a feature in the endings which I don't really find funny at all.