In my experience, the following are factors to consider:
1) Flat, solid surface - build the sukkah on as even of a surface as possible. Grass is the worst, for setting a table and chairs down and hoping they won't wobble. Dirt is slightly better.
2) Close to your house - build the sukkah close to your house, preferably near the closest entrance to your kitchen. This minimizes the length of trips to bring out and clear food, and for bringing out the sukkah materials from your garage/storage room when you build the sukkah.
3) Private - build your sukkah in the backyard, if possible. You will have more privacy, which is especially important for sleeping in the sukkah.
4) Against a wall of your house - if you build your sukkah against the wall of your house, you will have one less wall to build, and an easy, sturdy mount for the s'chach. If you can, put it in a convex corner of the house, with two walls! (Be careful about roof overhangs, which will invalidate some of your sukkah area.)
5) Not attached to a door - this is my personal opinion, but it is annoying to have the sukkah attached to the house, both for the people in the sukkah who now have house-traffic going through, and for the people who want to go out and have to circumvent the often crowded obstacles in the sukkah.
That being said, good places for the sukkah are:
1) A Deck
If you have a deck, that is the ideal spot for a sukkah. It is a flat surface, is close to your house, and often has railings tall enough to count for at least one wall. Decks are usually private, in your backyard. You may have to violate rule 5, but it's worth it.
2) A Patio
Patios are also generally smooth, flat surfaces, and are usually coming off a door to the house. You can also usually leave a small amount of space between the house-entrance and the sukkah.
3) Back end of your driveway
If your driveway goes around the side of your house, the back corner of your driveway can be a good spot. It is flat, often has quick access to space that can be used for sukkah-supplies (the garage), and can still be out of the way, if your driveway is large enough. Try not to ruin your kids' basketball court, though.