I restore older cars and work on a lot of rusted and corroded fasteners. I have found that these Granco line wrenches are absolutely superior in removing stubborn nuts and bolts over just about any other set I own. They have extra deep heads which greatly increase contact surface area.
Although not considered "main stream", they are truely worth a look -- Granco is an established US company and they make an excellent line of tools.
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/misc/PICT0268Medium.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/misc/PICT0269Medium.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/misc/PICT0270Medium.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/misc/PICT0271Medium.jpg)