For chips: bake chunks of potatoes in the oven with a lot of olive oil, some Tempeh and a bit of vinegar and salt.
Chocolate: get used to very dark chocolate, so dark it contains little sugar. This is actually very healthy. It is the sugar and any unhealthy oils, that makes a chocolate bar unhealthy.
Nachos: The beans in nachos are actually very healthy. Increasing your consumption of beans any way you can is good thing. Take a corn tortilla, heat it with olive oil, add lots of refried beans made with more olive oil, a small amount of real cheese, and lot of fresh salsa (fresh tomatoes, peppers, cilantro, etc). Quite healthy homemake nachos.
Sodas: I dilute fruit juice and add rose water, vanilla flavoring and vinegar or limon juice to a get soda-like taste that's not at all sweet (I think that even regular fruit juice is too sweet to be a soda substitute). Cafe Gratitude, among other health food restaurants, has some appealing sodas.
-- The oil in foods is often what can give one a feeling of satisfaction. "Junks foods" exploit this along with the "sugar" rush. But oil isn't necessarily bad at all. Rather, what's important is getting a good supply of good oil (especially olive) and avoiding really bad oil like transfat.
Jeanne Calment lived to the oldest documented age ever - "She ascribed her longevity and relatively youthful appearance for her age to olive oil, which she said she poured on all her food and rubbed onto her skin, as well as a diet of port wine, and ate nearly one kilo of chocolate every week."
http://en.wikipedia.org/wiki/Jeanne_Calment
I'm not sure about the port wine though.