Favorite energy gels/fuel?

I am interested in what different nutrition sources people like best as I have been wanting to try some new ones before I really lock in and begin training for my full-length Ironman in October. I personally really like the fruit smoothie flavor of the Stinger energy gels but those do not have caffeine (and I am not a fan of the Stinger strawberry kiwi flavor, which is their flavor that has caffeine).

Please drop your favorite caffeinated/uncaffeinated gels or any other sources of nutrition you like!