QuickTime X is a very good, comprehensive program with flawless operation and performance, but something is missing. That something is the customization options, which are practically null and do not give us the option to customize the player as we want.
But if Apple doesn't give you something, the Maquera community will give it to you. And from there QuickTime X Preference Pane has emerged, which will give us the customization options that Apple did not offer us (well, with Terminal commands).
Download and use is free, so if you have Snow Leopard, it would be practically a crime not to install it.
Link | QuickTime X Preference Pane