Like Deeds said you definitely want BAWLS and Gamer Grub. They are more expensive and still sale like crazy because they aren't found just anywhere.
I'm the only place in the area with BAWLS. Gamer Grub can be found at Toy's R Us in some places but if you can get it the gamers go nuts over it and it tastes pretty good too.
Drink distributors offer a lot of choices I think the Coca Cola here has 20 flavors of monster, NOS, Full Throttle, ect. Any specialty items they offer seem to do well. PEACE TEA is big here also through coca cola. Arnold Palmer now made by Arizona is popular so I pick up a case or two when I see it usually at Bilo the mark up is enough to make it worth having.
We offer around 10 different soda's, gatorade, fruit juices, 5 flavors of tea, lemonade, water, yoo hoo, frappacino, and 10 different energy drinks (including 3 flavors of bawls John stops by and sells them to me on his way to his Columbus GA store!). Sam's club and Costco can usually beat distributor prices however their drink selection isn't as broad.
Snacks and candy we use Sam's Club. Chips, candy bars, cookies, rice krispy treats, slim jims, other beef jerky, suckers, air heads, m&m's, reeces pieces, kit kats, reece cups, Laffy taffy, sour straws, sour patch kids, ANYTHING SALTY OR SOUR enough to get them to buy more drinks. Oh and pop tarts we have strawberry pop tarts and kids buy them up like crazy...
We were asked to do healthy snacks once upon a time so we picked up chex mix, trail mix, other granola type foods and absolutely no one bought them. Including the person that requested those items. We take suggestions from regulars seriously if enough people ask for a certain snack and sam's has it we'll try a box out and if it sells well we buy it to sell here. Sam's doesn't charge tax on any resell items I'm sure most wholesale stores sell tax free to resellers.