AKICILJ: IMAP clients

[kjn]

I've spent some time trying to get Thunderbird to behave, but it simply has too many misbehaviours (eg not realising that different folders need to be able to show different columns of information) - and it's not like I lack experience with e-mail programs.

So, what is the best program to use with a Gmail account using IMAP, and any really good tips for making it work?

I'm on a Vista SP1 machine.