I've got a few favorites in my dice collection, including individual pieces and sets. I would like to say that any of my Gamescience dice made the cut, but, alas, they did not. I don't have any pictures of these to share with you, but since we're all good at using our imagination, let's do that.
My most recent find is this off-white 20-sided D5 that I have. It came in the ubiquitous Pound-O-Dice product that we are no doubt all familiar with. I've been looking for something like that for a long time. Now I just need a 20-sided D10 and I'm a happy camper.
My other favorite is a set of mini Dwarven Stones made from some sort of green semi-precious stone, and I forget the name of said stone. They're a far cry from precise, but they're fun. I also have a set of small Koplow gray/black dice with a silvery finish that a pretty awesome. I like small dice, yes.
I also like big dice. I have a gigantic D20 that I give people when I think they've had one too many good rolls without my eyes on them. I have a big ol' D6 and D4 for the same reasons. That and it unnerves the players when I toss those out on the table for attack and damage rolls!