Ubuntu Maverick vs. Natty vs. Mint vs. Elementary

Here you can compare the default interfaces of the different Ubuntu versions and the derivates Linux Mint and Elementary OS. Which design do you prefer?
I'll examine the differences between the different versions in an upcoming post.

Ubuntu 10.10 (Maverick Meerkat)

Ubuntu 11.04 (Natty Narwhal)

Linux Mint

Elementary OS