Uhh... Expression what again? You actually never heard about it? Well, it was the same with me, but then I saw the wonderful blog of the talented Veerle Pieters, and saw there, that she uses Expression Engine, so I had to check it out, and you should to!

Expression Engine Features
Expression Engine Pricing - don't worry, a free core version is also available

What I like the most in Expression Engine, that there are no limits set, you can transform any (x)html-css combo into a dynamic database driven site exactly the way you want it after only a really short learning period - well it took just 4 hours in my case. There is really nothing I think you could not display with the smart Expression Engine Tags. My clear advice is, if you are in the search for a new, very easy to learn/use robust content management system, give it a try, you won't be disappointed.