I hate having stripped bolts. I've used the 'Grabit' line of screw/bolt extractors and it worked very very well for me. Canadian Tire sells it, under the house brand name. Use it with a drill and in reverse mode. Then flip over the bit and use the other end, but do it by hand with a bit driver and slowly you'll get it out! They have infomercials for this thing...but it works very well!
And a youtube video showing how to use...