Green with Mametchi. <3 I mainly got it because Mametchi's my favorite.
Even though these are probably my favorite Tamas, I most likely won't be getting another one until Tama-go v2 or whatever. They're a bit too bulky and expensive to get more than one for me. :Y
I just received a green one in the mail from Bandai, which is awesome because Mametchi is one of my favorite characters. I am tempted to get all 3 because I go out of my way to make sure I get Tamagotchis that have blue in the design (my favorite color) and I like the way the white one looks. We'll see. In addition to the green one I have now, I'm most likely going to at least get the blue one so that I can have 2 to connect.