Sensible option: L.L. Bean, $40 
Splurge option: Norse Projects, $198 
Why dad needs it: If your dad was the one who introduced you to the great outdoors, then it's high time you give him something that'll let him continue to enjoy all of nature's splendor, even if the weather turns real shitty. Not that a little rain would ever stop your dad, but now he can stay dry and keep it crispy.