The Eureka Lemon (aka Garey's Eureka) is an extremely popular lemon originating form Sicily. Its medium size fruit is tart and juicy, highly acidic and has a few seeds.
The Lisbon lemon tree is one of the most commonly grown lemon in California because it is resistant to environmental conditions like frost, heat, wind and neglect. The tree grows extremely large and is very thorny.
The Meyer lemon has a milder, less acidic flavor due to being a cross between a mandarin or orange and a lemon. It grows well in pots and substitutes well for a real lemon if you live in a colder climate.