It honestly depends on what I'm eating/drinking. With drinks, vanilla or chocolate are generally my go to thing. Vanilla coke is the best. I also like adding vanilla to some other sodas. Chocolate also goes well in soda, I think. I grew up getting chocolate cokes from Sonic all the time.

As for food, I don't know that I have a go to flavor. I like peanut butter with a lot of sweeter foods. I cannot do mint. Ever. I don't like mint in any form for various reasons. For non-sweet foods, I add hot sauce to a lot of stuff. Otherwise, I don't really have many go to flavors.