OGRE 1.0 Released
Amit Mathew writes "The OGRE (Object-oriented Graphics Rendering Engine) team released version 1.0 (Azathoth). OGRE is currently the premiere open source graphics engine and is used in several commercial projects and hundreds of academic and hobbyist projects. OGRE has an active user community and features advanced shader support, multiple shadow techniques, and much more!"
I'm not sure about FOSS games, but I'm sure that they're out there. However, one of the IGF finalists, Supremacy, uses OGRE for the graphics end of things.
Christopher S. 'coldacid' Charabaruk -- coldacid.net
Ogre Projects
List of projects that use Ogre, including quite a few games, some being OSS, some being commericial.
While not open source, Garagegames recently released the Early Adoptors version of Torque 2D for which you get the source to.
(Torque is the engine used for Tribes 1/2)
It makes making cheap little (or large!) 2D games a snap.
that will peak the interest of another company
"pique".
So as long as you don't mind shipping all the object code to your commercial program, you can use the library. Sure they tell you to read the full license, but only after failing to neglect the most onerous part.