My Chicken Coop
This 20 ft dog concrete paved dog run was the base for my new coop (May 2010):

It has a full-sized chain-link door, a concrete foundation, a chain-link roof, and perfectly good supports. The dog kennel frame is made of steel angle iron with pre-drilled holes.
Here's what I turned it into:

Note that the chicken wire doesn't block access to my firewood, and everyone in the family can access the nestbox without getting poop on their shoes! Here's the coop completely finished, and inhabited:

Chicken coop and run: 20 ft paved dog run with top, back, and door already in place. It is now a 15 ft chicken run with an upper level coop. The roof was completely rotten, so I replaced it with a piece of plywood with some leftover roofing shingles from a neighbor who was getting a new roof.

The coop is 4'x3'

What I like:
Cheap ($65 for what I had to buy)
I used some leftover lumber from other projects
Water-sealed with outdoor varnish to guard against the elements
Stained so that it looks less ghetto
I can walk inside without crawling to clean it out and change water / food
Anyone (incld wife and 4 yr old daughter) can gather eggs without going inside where the poop is
The chickens can go in and out of the coop by themselves
The coop has ventilation for TX Summer(1" air gaps at top\)
The coop and run is big enough for a few more chickens if I want to grow my flock
The coop has a perch/roost

What I don't like:
I am 5'11" and the coop is 5'8"
I didn't overhang the shingles enough on one side, so the water may drip onto the plywood, shortening its life
The coop is not predator proof (gap above door), but I don't worry about this b/c I close their coop door every night)
When they were little, they found some gaps that they could sqeeze through near the fence. (I closed them up with some left over lumber and zip ties (free)
I haven't built a hanging waterer. They knock over the waterer every other day
My feeder is not perfect yet. They spill seed all the time (I'm worried about rodents. Rodents attract snakes and coons)
I would paint it instead of staining it, but that costs more money. After all... it's a chicken coop
Not enough ventilation. All summer they roosted on the ladder and on the floor of the coop.
The dowel roost is too narrow... they don't use it. Next time I'll use a 2x4
Mod: The cabinet door became the nighttime roost, until it fell off its hinges from their weight. I need to install a sliding coop door.
Mod 2: I added a small piece of plywood to make the nestbox more enclosed. They were laying in the coop, which made egg collection difficult. Once I added the 4" tall piece to keep the shavings in, VOILA! Eggs were where they were supposed to be!