I would like a blog or other appropriate system installing on a webhost.
I would recommend using Wordpress 2.x, including the following features:
-Ability to post clickable thumbnails which reveal full-size Lightbox images
-Can link to videos from external sites e.g. youtube, google video
-Allow invididual posts to be rated (e.g. out of 5)
-Ability to list top rated entries
The backend should be simple to use, which is why Wordpress is recommended. I quite like the "Fluid Solution" theme.
I don't mind if you choose existing plugins but they must work without any security issues and with most browsers.