Those of us who have been wargaming for a long time remember when Six Sided Dice (or simply "D6") where all we had to work with. Then the fantasy gamers (yes wargamers do have a debt of gratitude for that) brought us a bunch of different types (D4, D8, D10, D12,D20). Of course, if you have been wargaming a long time, you probably also built up quite a collection of 6 sided dice :D
Now I've always been a fan of changing up the Dice number and types (for purposes of variety if nothing else), but I always seem to come back to the good 'ole D6 time after time for certain things. Currently, I tend to use a mixture of dice types in my games, as it makes it easier to remember, say '2d6 for Morale' and '1d10' for combat, etc.
In my 15mm World War 2 ruleset, I use the 2d6 to determine ordinance To Hit results. If a hit occurs, I use 2d6 also for penetration, but also a D30 (yes a wierd die but useful on occasion) to determine if any extra damage is incurred (say hitting a gun, or hatch, or whatever based on the target facing).
The 2d6 I use for the To Hit process is actually one colored (red) die and one white die. Not only does it determine if a hit is made, it determines where on the vehicle it his (if the colored die > white die, it is a turret hit otherwise it is a hull hit). This "two for one" deal speeds things up (as if you get too many die rolls you wind up with old Avalon Hill's almost unplayable Tobruk). If the to hit roll is snake-eyes, it is a critical hit. If it is Box-cars, it is a miss and may break the gun. This same roll can also cause a loss of a particular sort of ammo (AP/HE/APCR./HEAT etc) if stowage is limited with that particular piece of ordinance.
I also use 2d6 for determining Morale checks. You roll 2d6 + modifiers <= that unit's morale to be ok. This tends to work out well, since the average roll is 7, so the average morale is 7 also. It works out well and allows things such as Heroism (rolling snake eyes) or Cowardice (rolling Boxcars).
Now a lot of this I owe to AH's old Squad Leader of which I was (and still am) a big fan. Still, a good idea never dies, they just keep coming back again and again.......