I'm sure you've all heard this one, but REALLY, you need to go out and buy it asap.

Erwin Chemerinsky's Constitutional Law Principles and Policies (3rd Ed). It's published by Aspen.

It's fantastic at explaning how all of the cases relate to each other, what would happen if a justice decided to vote a different way in a future case, and problems of different theories. It has subheadings of all the different issues that could come up under that particular topic, so you'd just have to flip to that page when working through a hypo.

I think gilbert's puts out a great supplement too. clear and easy to follow.

I like the gilberts outline also, but the hornbook she is talking about is good, but thick.