This stuff:
I used it for the first time last weekend to free a brake drum from it's hub on a 2000 Camry where the drum had never been removed. I tried it on a previous occasion where I just used the bolts to force the drum out and ended up ruining the thread holes. When I used the PB Blaster and let it soak in (really only for a few minutes) removing the brake drum was actually pretty easy.
I can't believe that I didn't buy this product a long time ago! It's really that good.