Picturenaut
"If you are looking for straight forward images without excessive tone mapping this has to be your top software. Provides image alignment, exposure correction, color balancing, noise level compensation, and derivation of the camera curve from the source images."
http://www.hdrlabs.com/picturenaut/index.html
When HDR-programmes are tested, another programme: fdrtools, gets a very high score.
Fdrtools des have a freeware version:
www.fdrtools.com