Hybrid cars accelerate more slowly than non hybrid cars. They can be more expensive to buy and repair. There is a high demand for some hybrids and there are waiting lists to purchase them.
Hybrid cars cost a fair amount more than a regular gasoline driven car and their increase in mpg is dependent on your driving. It depends on a certain range of speed to achieve the better mpg. If you have a heavy gas foot you won't get the good mileage.
If you purchase an Electric car you are going to have to have an area available where you can plug the car in to charge. Smaller towns don't usually offer public areas where you can park and plug. If your car requires Bio-fuel once again it's the convenience issue. Check to see if it's available in your area beforehand.
Hybrid cars have more internal components and more interactions between those components, so there's a greater liklihood of something going wrong. And when something does break, a lot of smaller mechanics aren't educated on working with hybrid vehicles. Plus, in general, Hybrid vehicles tend to cost 15-20 thousand dollars more than conventionally-powered vehicles.