I've used a bunch of URL shorteners before but I am really impressed by Short.lc - The webpage is extremely quick and provides exactly what it says. Another plus that this page offers is the ability to post links on webpages such as Reddit and 4chan without a spam filter activating. (Most other URL shorten programs and websites I've used tend to get blocked, but Short.lc works like a charm.)
I'm really impressed and use this all the time! 5 *s!