How to Fix an Unresponsive Finder

Problem: After upgrading to Mavericks (Mac OS X 10.9), Finder is extremely sluggish

Solution: Type the following in a Terminal window:

rm ~/Library/Preferences/com.apple.finder.plist && killall Finder

This deletes Finder's preferences then restarts Finder. Warning: you will need to reconfigure Finder's settings (for example, the way the icons are arranged on the Desktop).