The key to a successful business is finding the "pain"/problem or desire that people are having and you sell them the solution. Make sense?
Identify the Paying Market first, Product/Service second.
Personally, I prefer the type of business that will make recurring sales such as recurring membership site subscription, sales of consumable products and services etc.
This list will expand with more and more ideas:
- Start a Vending Machine Business.
- Start an Online Store offering daily sales on top-quality boutique apparel, gear and other goodies for moms, babies and kids.
- Start a Pet Grooming Business.
- Start an Online Store offering laptop batteries, digital camera batteries, camcorder batteries, battery chargers, AC adapters and DC adapters.
- Start a Pet Food and Supplies Business.
- Start an Online Store offering a large selections of socks.
- Start a Veterinary Care and Medical Supplies Business.
- Start a Craft Business.
- Start a Coin-operated Laundry Business.
- Start a Bed-and-Breakfast Business.