Being severely lactose intolerant, I would have to say frozen yogurt. I don't care how hot it is outside or how inviting the yogurt place is, that stuff is a disaster in a cup. If I know I am going to finish my ride near a strip mall with a yogurt place, I pack some lactose pills. But I will never ever eat that stuff on a stop during a ride. Ever.

I have heard of some people taking hard boiled eggs with a dash of salt on a ride; doesn't sound like a bad thing to eat, if you like egg whites (which I don't- stuff is like rubber, but I love egg yellow.) Citrus fruits are out- give me heartburn big time.

Once I had a big tuna salad at the half way point, oh that was a mistake. I belched tuna all the way back to the car. Lunch is one thing that I can't stand reliving as I ride.

Bananas, which I don't like, I will eat on a ride at the drop of a hat. They never cause me grief, other than the taste, which I tolerate. They digest easy and don't come back to haunt me, and force me to drink water, which is a good thing. But I will not eat them at any other time. I also like rice-cakes with peanut-butter. They don't get squished up like a bread sandwich can.