For as long as I can remember, the FA's come down the aisle with either bags or a basket of snacks. They typically carry 2 or 3 items. At least one of those items is always peanuts/pretzels.
Belvita (has become more frequent in the past few months)
Wheat Thins (seeing these less often)
peanuts (it's currently honey roasted peanut season

)
pretzels
I've never seen Fritos or ritz crackers.