I wrote about this exact topic on my blog, a couple of years ago:
http://eichy815.tumblr.com/post/158885169866/vivacious-vintage-vittles
My top choices:
Chachos quesadilla-style chips
Cookies-n-Creme Twix
Giggles cookies
Hardees Chicken Stix
KFC's original thin French fries (
not the massive potato wedges they currently have)
O'Boise's potato chips
Pizza Hut "Bigfoot" pizza
Pizzarias chips (apparently, TGI Friday's makes a "pizza chip" that closely emulates its flavor)
Taco Bell's Brownie Sandwich
Tropical-flavored Gatorade (
not to be confused with the fruit punch flavor)
Wendy's Chicken Caesar Pita
Honorable Mention to the McDonald's Onion Nuggets, which unfortunately were discontinued before I was even born -- but I would have loved to have tried them.
Do they even make Clearly Canadian ANYWHERE, nowadays? That was my favorite beverage in middle school.