As a compromise to combat patent trolls, litigation, the stifling of innovation, etc., how about changing the law so that once a patent changes hands it enters the public domain or ceases to be. It's imperfect, but has many benefits.
It would protect the initial inventor/patentor. You wouldn't have the same outcry as if you banned patents all together. However, is also a limitation as it would not stop litigation brought on by the original inventor. But it would put an end to patent trolls and would enable patents to enter the public domain at a much quicker rate. Sure, patent transactions would slow, but it's not unthinkable that a company would purchase a patent to protect itself from a lawsuit knowing that that very purchase will destroy the patent.