Dura blocks, motor guard, cut down hockey stick handles, tcp makes some nice blocks with a hard plastic base. Assilex makes nice Velcro blocks, really good for colorsanding. Also have 3m, and don't be afraid to glue Velcro onto your favorite block, or make your own blocks. Those foam noodles that they sell for kids to use in pools is good material for custom blocks. And then, there's the bondo and wax paper for those funky, custom sanding needs.
Harbor freight even has a decent block... the yellow one with the metal bottom, very flexible. Lets you block big corners and bends around them easily.
Yes, I have a ton of blocks. My favorites are definitely Durablock, just picked up another today... Lets you wrap 6" da around it, soft foam with hard plastic inside. Now I can start to burn through all of that extra da paper that around.