Boccano! was severely confusing. It tells the story from several points of view, but the events get really muddled and make it really hard to keep track of everything. The only memorable aspect is that the main characters are basically impossible to kill (you'll see why), but otherwise it's like slogging through a swamp. Good luck...
I felt the same way about Baccano! People were saying, "You'll be utterly confused after finishing the first episode, but eventually you'll piece together what all is happening". I finished the first episode; I was confused. I finished the last episode; I was still ****ing confused.
Thing is, reading the plot in Wikipedia, it's a good story, and I understand and remember all the events now
... but I didn't have a clue when watching. It's like a dense novel, if someone divided the novel into different pieces and mixmatched them.
The worst part about the show for me, personally, is that it's so highly praised, like it's a divine work of art, and I can't understand why. As a result, I feel like the main reason for my not enjoying it is my own stupidity; sort of the same way I feel about the novel, Ender's Game. But that's my own problem.
Durarara!! did a similar thing with its storytelling, but it was a hell of a lot more fluent and... chronological... and less ****ing confusing.