The most common snack food items I buy (kettle cooked potato chips or nuts on any given week) I feel guilty that I consume them so quickly. Say something is 10 servings. Nope, that's a maximum of 4. Whatever is the planned amount for a snack food item to last, it will never last that long. Unless bought in bulk, such as nuts/m&ms/raisins to mix together.
Oh, and these store bought muffins from a grocery store bakery. You know, the "big" style; I get blueberry (or bran rarely) muffins. Come in a pack of 4 from the bakery. You'd think "oh, a nice muffin once a day". Those muffins are gone in 48 hours from the purchase max.
My guilty pleasure is sushi. It is so darn expensive and really, but you know I'll be coming back to it mainly as I feel it's too hard to make myself (I'm not going to do things like get eel myself).
I don't feel guilty about it, but I eat meat plenty nowadays. For a relevant amount of time (about 2 years over a 2.5 year period) I didn't eat any meat, or just very sparingly. I try to stay away from red meat--still eat it though--but I eat plenty of white meat.