TRX Suspension Trainer
One of the most versatile (and lightest) pieces of exercise equipment. With this system you can perform a nearly infinite number of different exercises, and due to its size its great for travel. (If the original TRX is out of your price range, there are tons of cheaper alternatives)
Great way to get your heart pumping and De-stress. (plus you'll have a stronger punch in just a few weeks, and you never know when that will come in handy)
Craigslist (I got mine in exchange for a old Sub-woofer)
Make Sure to Put it in a Highly Accessible & Visited Spot, such as a Living Room or Bedroom, Most People who buy Punching Bags Put them in Cold, Dark, Wet Places like Basements or Garages and are then surprised why no-one ever goes there to use it
The Only Set of Dumbbells you'll Ever Need!
Can be set to weight from 10lbs to 90lbs.
For those that are a bit less intense there is the SelcetTech 552 that go from 5-52lb.
If you want a deal, grab them on craigslist (that's where i got mine).