I've read Stephen Hawking's A Brief History of Time. It's an accessible, but still very interesting read about cosmology and the search for the Grand Unified Theory.

I've read quite a bit of popular fiction as well as a few papers on physics theories, and now I'm really not that interested at this moment of time. I'm a bit busy to start reading into endless thought experiments. Not that they're pointless, but there's a real world out there.