I don’t really use that at many defaults write terminal commands, but I read about this one recently and I like it a lot.
If you hide your dock, you can speed up the hide/show animation by using the following command in Terminal:
defaults write com.apple.dock autohide-time-modifier -float 0.5;killall Dock
This will make the animation much faster. You can also get rid of it completely, but I think that looks weird.