I'm a fan of the Odyssey dry cell batteries. I've used the PC625 in a couple cars. Plenty of juice for the typical 4-banger, and as a dry cell, there's nothing to spill. Super-lightweight, super-small, super-reliable, and really not all that expensive.

With Braille and Optima and such, you're paying a lot extra for a big brand name. (and before the Odyssey secret started getting out, you could get one for $80... now they're over $100)

Odyssey PC625 Battery - Free Shipping: BatteryMart.com