Helloooooow my avatar has a black hand FO SHO!!!

So last night i was twurling around in my bed because i couldn't sleep and started thinking;"What would be a good idea for a game?" Well i'm not really sure it is a good idea, but i'll keep it a secret. There is only one problem. I don't know where to start! My PC crashed the other day, meaning i lost every little program what i had. I'll start downloading and installing stuff. Do you know any good programs to use?