Website Loading Slowly

One of my websites takes 60+ seconds to load. The other website is exactly the same except that the homepage loads normally but sub-pages load slooooooowly.

WordPress: 3.5.1
Host: Godaddy

Plug-Ins: I have deactivated all plug-ins and turned them on one by one to see if it helps. No change. I also ran a plug-in called P3 (Plugin Performance Profiler) which says there are no problems with the plug-ins.

Theme: I deactivated my current theme and activated the default theme, but the site still loads exceptionally slowly.

Database: I used a plug-in called WP Optimizer to optimize the database. Nothing changed.

Server: I’ve been in contact with Godaddy, they say there is nothing wrong with their server.

One interesting observation is that the dashboard loads normally. Everything in the back-end works like it should. It’s only the Frontend loads so slowly.

I’m not sure what else to look at, can someone please help me figure out what to try next or even help me figure out what could be slowing everything down?

Thanks!