I use GMail (and I use labels intensively) and because of having to use a very slow Internet connection now I've came to the idea that I should try using a desktop email client.

What application (Thunderbird, Evolution, Claws, or some another) works best with GMail via IMAP?

First of all I want correct GMail labels support (for example an email client shouldn't think of GMail labels as of independent folders, treating messages with multiple labels as multiple different identical messages in different folders), incl. special GMail labels-folders like bin, spam, drafts and sent.