Are there any pitch/gdd's for any games floating around? I'm just curious to see what a professional game pitch looks like and how in-depth they are.

Considering such (professional) documents are generally...confidential, somebody isn't doing their job if they're just...floating around.

Chris Taylor has a template.

If you dig around the net there are actually quite a few available that you can find. Unfortunately I can't share any from work due to well, my company owning the rights to them. I've worked on quite a few though, so I could provide feedback for any documentation you produce.

Below are some pretty cool resources -

Shred Nebula
Play with Fire
The ever awesome Tom Sloper's website