Cathy's right. I made *a lot* of banana bread -- essentially anytime I've got old bananas. When I've set out to make the bread out of choice rather than necessity, invariably the results are worse. Why? Because it's difficult to wait long enough for the bananas to ripen. If you can slice the bananas, they're the wrong bananas. They should be rather mottled and caramelly -- on the inside. The outsides should be essentially blackened. You can speed up the process by leaving them in a closed bag at room temp.
I like Cook's Illustrated's recipe:
2 C flour
1 1/4 chopped toasted walnuts
3/4 C sugar
3/4 t baking soda
1/2 t salt
3 very ripe mashed bananas
1/4 C plain yogurt
2 large eggs lightly beaten
6 T unsalted butter melted and cooled
1 t vanilla extract
Basically you sift together the dry ingredients and mix together the wet ingredients separately. Then fold in the dry ingredients. (Stirring too much builds gluten and makes it chewy.) Bake in a greased 9x5 loaf pan at 350 until a toothpick comes out clean, about 55 minutes. I like it to be a little underdone, myself. Also, I think vanilla or strawberry-banana yogurt can be nice, too. Also, a little honey added to the wet ingredients can be nice.
It's a relatively dense banana bread, but not as brickish as some. Warm with butter is divine.