Some people pack an el-cheapo rain poncho while others swear by their super-high-tech waterproof/breathable jacket, all of which illustrates an important point: Getting the right shell has as much to do with personal needs and hiking habitats as it does with the quality of a garment. In other words, buying more jacket than you need makes no more sense than buying less jacket than you need.
Ask yourself a few questions: What range of temperatures do I normally encounter-rarely below 45? F or sometimes below freezing? Is there a high likelihood you'll encounter snow and frigid winds, or monsoonlike humidity? Do you want a jacket strictly for summer and early fall, or for all four seasons?
If you typically hike in mild weather, get a lightweight jacket. That is, a shell that weighs 20 ounces or less, has thin fabric, and a simple, stowable hood and low collar. The cold-weather warrior, on the other hand, needs armor-plated fabric, a batten-down-the-hatches hood with good adjustability, and a stiff collar to keep the elements off your neck. If you're not sure, consider whether you get cold easily or tend to sweat a lot. A cold person's safe bet is the warmer parka. A hot person will probably be happy most of the time with a lightweight jacket and can handle colder temps by layering underneath the shell.
Next, consider your personal physiology. If you perspire easily, you'll need pit zips, venting pockets, and a two-way front zipper. If you stay dry no matter how hard you work, skip the bells and whistles to save a few ounces.
Also look at how hard you treat your gear: If you like bushwhacking, scrambling, or climbing, look for fabric built to withstand abuse, plus reinforcement panels in high-friction areas like shoulders, elbows, and lower back.
Once you make your purchase, the best way to prolong the life of your waterproof/breathable investment is to keep it clean. All the test jackets come with a factory-applied water-repellent finish (DWR) that causes rain to bead up on the outer surface. This coating can become compromised by dirt, campfire smoke, even oils from your skin. Washing with a mild detergent and a trip through the drier on low heat often reactivates the beading properties. (Note: Always check manufacturer recommendations first; some advise using a nondetergent soap like Nikwax Tech Wash, while others recommend a small amount of powder detergent.)
Eventually, the DWR will wear off; you'll know because the shell will consistently "wet out" or appear to soak up water and it won't breathe properly. Some manufacturers recommend certain DWR-restoring products. Gore's Revivex and Tectron's Outdoor Fabric Protector performed the best in our review of DWR treatments (Outfitting, April 1998).
For more serious wear-and-tear problems, like delaminating seam tape, holes, busted hardware, or unraveling seams, consult the manufacturer about a warranty or a repair professional. For a list of repair shops: www.backpacker.com/repairguide.