The most common lemon variety is the Eureka lemon. Its slightly smaller, smoother cousin, called the Lisbon, is more likely to be available in the winter. There isn't much difference between the flavor of a Lisbon and an Eureka.
The Meyer lemon, is quite small and significantly sweeter than the ordinary lemon varieties.Meyer lemons are more floral and less acidic than regular lemons. Use the juice, zest or even whole slices to make wonderful treats!
I love lemon so much, that I have my own Meyer Lemon tree growing in a container. I'm serious about lemons. They aren't just for iced tea!