I use Megaproxy's paid-for service which works out at about $2 a month and comes with some nice toys to do with anonymity, popups and security settings. Surfing is done via a secure HTTPS window, no modifications are needed to software on your PC. Great for accessing web servers with funny port numbers through a strict firewall too.

However, if you're planning to do anything illegal, don't rely on any proxy outfit to protect your details. Despite all the claims they make, they'd tend to buckle fairly quickly if visited by the CIA