Shotgunning
Seriously, it's kick ass. You don't need to hunt, you can play trap or skeet. They are fast paced games so you're not just waiting around for a target. You can spend as much or as little as you like, add fancy attachments for your gun or you can just keep it simple. Your biggest expense after getting a gun and a club membership (if you choose that route) is ammo. On the high end, that's $15 for a box of 25 shells.
I've really found it a fun and rewarding hobby without all the shitty cleanup. Cooking, you gotta clean the kitchen. Gardening, you gotta weed (and not the fun smoking kind), hiking, biking, kayaking - that stuff is fun at first and then it's like fucking work.
Go blow some plates up - amazing stress reliever, no messy clean up (like wanking) and no one judges how good or bad you are - you are carrying a gun after all
Here's my Benelli Nova 12 gauge pump shotgun:
Word of warning, buying guns can be addictive!