I voted for "other": Coming from doing nothing, there is a lot you can do without a home gym or a membership. I'd just start with brisk walks and put a goal (time and or distance every week). Once you have that routine, I'd worry about getting more serious.
Personally I am blessed living in SoCal, so I can always go run or bike. I do have a family gym membership and mainly use it for yoga / strength classes and once a week lap swimming. That said, the majority of my cardio exercise is done with a dog or two on leash cruising the neighborhood or the local hills.
Yes, if you can, get a dog.
Finally, come visit us in the weight loss and fitness challenge thread (sticky in PPOT) and set a goal. Even an easy goal! It works.
G