Since my favorite are extinct, I've got to go with my second favorite: Giant Day geckos (grandis). They are beautiful, green, and not so hard to find in a well constructed cage. In 99 out of 100 cases, day geckos are living paintings: beautiful to look at but NOT FOR TOUCHING. If you want a reptile you can take out and touch without having them escape, rip skin from their body, and throw tails - day geckos are not what you want! However, if you want a relatively easy lizard to care for ONCE THE CAGE IS SET UP PROPERLY, then day geckos might be for you....especially if what you want is a cage and lizard that is prettier to look at than any others out there (my opinion, only).
KJ