10 sites with content diffrent and diffrent themes... help

i got a problem:

lets say i want to have a you tube like video site , i want to have 10 drupals so ill be able to make "moviecms.com" and "celebcms.com" ,all of them are in the same core, and i just want them to look diffrent and shows diffrent movies and ads ...
i dont mind even to get one admin and not giving users access or just disable the whole user feature and update the content trough a php script that ill do

i looked up alot here and didnt find the right solution and if i did its not worked because so many users are comments what the diffrent method so i got mad

i got a dedicated server , linux, ssh root, ubuntu , mysql php and everything

anyone can help me to find the best solution to my needs or somthing similar to that?