Well, if youre indeed a big, sweaty backpackerand I am trying VERY hard not to conjure a mental imageare you sure you got wet from the outside-in, or was it from the inside-out? Because even the best waterproof-breathable apparel, in the right conditions, can leave you plenty damp and sweaty. But, I know it was raining in your part of the world about the time you got soaked, so Ill assume your jacket leaked. There are lots of good choices out there, and theres no real reason to spend a ton of money.
Pretty much the gold standard in well-priced rainwear is Marmots PreCip Jacket ($99; www.marmot.com), which completely subverted an outerwear market that was getting rather out of hand with $499 jackets. Its waterproof, offers reasonable breathability, and is loaded with user-friendly features such as a hood, armpit zippers, and storm flap. Its not for a lot of grubbing around rocks, trees, and sand, but a good when-you-need-it jacket.
For something a little more luxe, Patagonias Rain Shadow Jacket ($149; www.patagonia.com) offers polyurethane-based waterproofing similar to that found on the PreCip, along with a sturdier outer shell (ripstop nylon), pit zips, and hood. Its also pretty stylish, in case you want to wear it around Athens between trips.
Next up, you can get into Gore-Tex PacLite, a slightly pared-down version of regular Gore-Tex that saves weight and keeps you dry while cutting back a bit on durability. Outdoor Researchs Celestial Jacket ($249; www.outdoorresearch.com) is an excellent application of this fabric, with big side zips for ventilation, taped seams, and water-resistant zippers. For backpacking, it may be close to the ideal jacket, offering lightweight (only ten ounces) and serious weather protection.
Now, when you say unfiltered water," you mean as in unfiltered tap water"? Excessively hard water isnt easy on any kind of fabric, but otherwise, sure. All gear makers run extensive washing tests on their stuff, subjecting most items to aggressive 25 to 30 wash cycles to test for durability and the resistance of the DWR (durable water repellent) coating to detergents. Use a touch of water softener if needed in your area, but DO NOT use an anti-static or softening product in the dryer. Those leave a waxy coating on clothing that can make it less breathable.
Check out this years more than 400 must-have gear items, including a comprehensive hiking section, in the 2006 Buyers Guide.