I've got three today, and they're all available on Hulu and I recommend hunting them all down. (At least one has no Youtube presence; I did look.)
First is New Amsterdam. This is a hard one to describe because it doesn't really have a hook, it's just very, very pretty. Disappointing show, but I never got tired of the title sequence.
Second is Chuck. The little Nerd Herd guy is cute, yeah, but he's barely a reason. I love the monochrome look, and the still frames, and I have an irrational love for the label-maker font on everything. And the music, oh the music. Three seasons, and I still dance every time.
Last but definitely not least is Raines. In an unexpected and slightly subtle way, it sums up the entire premise of the show perfectly, in a way that makes you curious and fascinated and eager to see more. Even though none of the characters in the title sequence ever appear in the show (apart from Raines himself, of course), you can tell that there's a story behind each one. And you're dying to hear it.