How do I get reliable taxi transportation in Omaha, NE?

I currently need taxi cab transportation to my doctor and reliable transportation to the grocery store, and have a taxi to pick me up sometimes when I go out to my local bar. Many taxi drivers don't pick me up on time and increase the rates with extra charges. Some taxi drivers I don't really trust(look creepy) and I even had a cab driver get lost. Where do I find a driver that's courteous, dependable, knows all the destinations in Omaha? I have been using taxi cabs for transportation for 2 years and still havn't found one that I can depend on and I also want my cab driver to be CLEAN. Where are you?