A good torch should make you unafraid to go anywhere, regardless of conditions. To take your trusty torch and make it even more durable, consider the bicycle inner tube adaptation shown off by an Instructables user.
TyrenRaven shows how a standard Maglite-style torch can be made resistant to whatever Mother Nature (or your basement pipes, or the water bottle in your backpack) can dish out. You'll need a standard bicycle tyre you're not planning on using, and not a self-sealing model, either. Beyond that, it's a matter of measuring carefully, cutting in, and leaving some room for things like the plastic sandwich bag cover that goes over the lens.
At the end, you've got an airtight canister for your trusted torch, on the cheap, but not chintzy.
Quick Easy Waterproof Flashlight using an inner tube [Instructables]