Cheez-Its are great!
Other mass-produced / pre-packaged favorites include Friday's Potato Skins Chips, Combos (pepperoni pizza), ketchup flavored chips, and All Dressed Chips.
I also love any meat snack, like Slim Jims or any sort of jerkey, etc.
Relatedly, "ploughman's lunch" type foods -- crusty sourdough with pickles and cheese and meat.
If we're talking about stuff made at home, favorites include peanut butter pie, banana pudding, English toffee (and the poor man's version, "Christmas Crack," made with saltines), sponge toffee, etc.
For quick salty/sweet combos, I like pairing a handfull of peanuts or pretzels or saltines with a handful of chocolate chips or m&ms.
My wife and I have a couple of favorite things we sometimes make for easy dates at home after the kids go to bed:
For one, we spread goat cheese on naan, then put roasted red peppers on, then drizzle the whole thing with a balsamic glaze.
For another, we lay out kettle chips across a cookie sheet, then sprinkle bleu cheese crumbles generously across the bunch, then a little bleu cheese dressing, then some balsamic glaze, then put the whole thing under the broiler to melt it down into the chips.
(You'd think from this post that I'm a sedentary glutton! I lift, and am often quite intentional about what I eat, sometimes go stretches eating only whole foods, sometimes fast, etc. I'm just listing things that I especially enjoy when I do have them, but I don't have them often at all.)