I used to be a real folding station before I started to open up my game, but I still think I can find that fold button more often than most. My biggest fold so far was a nut flush on a non paired fourflushed board where only a straight flush that needed both hole cards could beat me (folded to river reraise shove).

Playing 100BB deep it's not very common to see big folds though. Folding AA is about as big as they come. Limped multiway pots are good candidates for big folds of course. Folding the second nut flush on a fourflushed boards is a big fold sometimes, but obviously pretty standard.

I still think that opportunities to make big folds don't come around often enough to have a huge impact on results, as they are usually very marginal situations anyway.

My all time favorite big fold is this one by Toadstool:
http://www.flopturnriver.com/phpBB2/...ot-t60645.html