My story:

I use real info. I was hacked and a domain was stolen with godaddy. To get it back you have to fax ID with your real name/address on it to match the registration info. If I didn't use my real info, I wouldn't have had the domain back in my account within a couple hours.

Plus if somebody reports your site for using fake info (dmca company maybe) you may lose your domain. A member here had a dmca notice mailed to him. Had he used fake details, he wouldn't have received it and things may have escalated.