Favorite beverage would be Jamba Juice, in one of 4 or 5 favorite flavors. Unless it's chilly and we're too poor for Jamba (which is most of the time), in which case it's hot tea (usually actually almost lukewarm by the time I'm done steeping it!).
Favorite snack is harder, because most of the things I like to snack on are either dusted with flavoring powder, or sticky, and therefore don't mix well with knitting. In general, my favorite snack is K.C. Masterpiece Lay's, but I also like more snooty chips.. such as the Cheddar Beer Kettle chips I have out as I type (which do not, by the way, go with Jamba Juice very well. *sigh*).