I try not to buy more than 1 five hour energy so that I'm forced to walk/drive to the store in the morning to get one. lol
got a box (12 packs) of Java gum, pretty good gum, and however much caffeine is in them is like perfect. picks you right up after like minute or two of chewing it, but not enough that you want to take a nap an hour or two later...
http://javagum.com
been giving a pack to friends, everyone loves it.
edit: just actually looked at the pricing, $10 for 4 packs (8 in each pack), but my buddy that sells tons of stuff on ebay gave me a box of I think 12 packs (6 spearmint 6 peppermint) for 10 bucks.
I assume you must get a decent discount ordering in bulk.