I prefer to take in one gel every half hour. My body seems to absorb it faster than solid food (don't know if there's any science behind that). This, along with Cytomax, fulfills my caloric needs, generally speaking.

One of my friends prefers the Cliff bar; every 20 minutes or so, he'll take just a nibble. This might be an option if you prefer the type of calories that you chew on.

As far as which brand, that's pretty subjective. I like Hammer gel apple for the flavor; however, I also use the Powerbar gel 4x sodium on the summer rides because I'm what is referred as a salty sweater. You'll have to experiment to see which brand works for you.

And don't forget the traditional options such as bananas, potatoes, sandwiches. Depending the length of your ride, it can't hurt to take in some protein (liquid or solid).