Brett Terpstra tweeted his favorite Mac OS X default[^spoiler]. It remove the delay before showing a hidden dock[^like]. My favorite might be “Make Text in Preview selectable:”
defaults write com.apple.finder QLEnableTextSelection -bool TRUE
[^spoiler]: *Spoiler:* defaults write com.apple.Dock autohide-delay -float
[^like]: Don’t get me wrong, I like that one too.