Drain away from house with slope, neat! Screw the fiberglass panels that form the under-deck roof to the purlins. This will be great for a shed to stay dry under the deck.
Outdoor 'man cave' - kitchen/fireplace/flat sreen tv, doesn't get any better than that
Deck over Patio + Landscaping
A slide is a great way to add fun and uniqueness to your two story deck.