Logitech Multimedia Keyboard Deluxe (Whilst' it's USB/PS2, I'm running it in PS2 mode)

Although you'll be hard-pressed to find it stand-alone, now you can only get it in wireless form with the "Wireless Desktop MX"

I like the way it works well with WinAMP (and under Windows it automatically works with WMP OOB without needing to install any extrware)

It, like the Microsoft one, has "F-Lock", but it isn't so much of an issue since after a while you turn it on by habit.