After a whole year of thinking about it yesterday i did it ! I bought Garry's Mod over Steam ! All because of a youtube link that a friend gave me. It is a really great sandboxeditor i totally recommend it. It cost 10 bucks and you get alot for that.
The mod community is very big so there will be no lack of content. I will post some screenshots of constructions that i made so stay tuned for some funny stuff.