I don't like screensavers...only times i use one is when i go outdoors for a couple hours, and then i use the "blank screen" one (i could turn of the monitor but as the switch on my monitor is kinda dodgy in turning it back on, i don't).
I used to leave mine on blank screen but since I discovered you can use videos I've set mine to this guy breaking with some SERIOUS power moves so I can study him. If anyone knows who he is, let me know!