Wow, childhood toy...I would have to say Lego. I was fanatic about building stuff with these blocks and I could never seem to have enough of them.
Adulthood toys. Now thats a hard 1 to choose. I got my computer and laptop, my ITouch which has pretty much replaced my PSP, my camera and equipment, my airsoft guns (a recent thing so small collection), snorkel gear, all my kitchen tools (still loving my Kitchenaid)...dude, you can't have me choose just 1!!!