For some games you just need a lot of dice, and these games tend to make use of six-sided dice. Enter the cube of dice, the 36d6 dice set. The huge number of dice in the 36d6 set is the answer to games like Champions and Shadowrun, as well as many war games and miniature games. The dice cubes use 12mm dice, which are substantially smaller than the standard 16mm dice sizes. Like 12 d6 sets, these dice sets use pips for numbering rather than roman numerals. Gamers unfamiliar with 12mm dice should be aware that though it doesn't sound that different from 16mm, the dice in the 36d6 dice cubes are really quite a lot smaller than standard dice.
Personally, for me, 36d6 dice sets will always be connected with Champions. I first played Champions with a gaming group of players also new to the game and a veteran GM. None of us players had anything close to the dice cube, and we showed up with our ragtag collection of D&D and World of Darkness dice woefully underprepared for the number of six-sided dice we would need to roll. We quickly learned that our GM, Jon, was a kind of idiot savant when it came to adding up all those d6 results in Champions. While we were going through adding up a giant roll, he'd get a glossy look on his face, nod to himself, and say "thirty seven" while we were only on our third die.
Probably the most satisfying thing about the 36 d6 dice cube is that it's just a lot of dice. And more dice is always a good thing.
For those that want a lot of d6 dice for their games but don't want the smaller 12mm size, you can also get 12d6 dice sets, which are standard-sized dice. Or, if you really want a lot of dice and are prepared to be completely random about the sizes and appearance, you can get the Pound o' D6.