I highly recommend pagelime mate. I have been using it for a few months now and it is really top class.
It is a remote content management system that works over ftp, so no database. You can edit any and all content regardless of the server-side language, you can create new pages based off templates, it has a built in code editor so some things like maintaining your sitemap.xml file or editing the robots.txt can be done within it. It can also have google analytics integrated into it.
With a blog module and iPhone app on the way for it you can't go wrong.
It is free for 3 websites but if you wish to skin it up and have it set up on cms.yourwebsite.com you will have to pay but even then it is very cheap, I think it is only $19 a month for 50 websites.
You can also get cc'ed when your clients request tech-support which I have found incredibly handy.