AdFly is one of the oldest high-paying URL shorteners that not only has a really good reputation but a track record of paying its link shrinkers (users) on time and a great place for advertisers to spend their marketing budget.
Bitly - Get the most out of your social and online marketing efforts. Own, understand and activate your best audience through the power of the link with Bitly Enterprise.
Polr - An open source URL shortener. A great non-profit and free alternative to bit.ly, TinyURL, or goo.gl.
TinyURL - Are you sick of posting URLs in emails only to have it break when sent causing the recipient to...
YOURLS - YOURLS is a website that contains all the tools you need to create and launch your very own URL shortener. URL shorteners like bitly or TinyURL are fine for public use, but they offer limited options in terms of URL customization.
Rebrandly - Rebrandly is the easiest way to create, share and manage branded links.
Shorte.st - Smart and easy way to get extra income from your traffic.