I need a markup editor

Hey guys.
I’m looking to do some simple HTML/CSS markup for a client, and I’d like suggestions on any good alternatives to good ol’ Notepad.

Ideally, what I’d like to have is colored tags, and perhaps even attribute suggestions (similar to Microsoft Visual Studios)

Oh, did I mention I’m looking for a free/open source solution? Does such a product exist, or am I stuck with Notepad?