My favorite instrumental without a doubt is "green onions" by Booker T and the MGs. Another sweet instrumental is "rebel rouser" by Duane Eddy. I have to add this story to accompany green onions. My friend and I were out on the town while my parents were away one summer. We had set out to steal a road sign because we were idiots at the time. But anyway green onions comes on the radio. My friend tried to change the station referring to it as a "crapstrumental". I wasn't going to let that stand. Anyway we turned, and saw a road sign, post and all, laying on the ground by the side of the road. So I drove up over the curb to grab it, tossed it in the truck, started to pull away. At that very instant a cop drove by and pulled a u-turn. I remember our reactions exactly. My friend and I turned and looked at each other, then I said "$--t" and he said "we're ****ed". We didn't get arrested luckily, but parents were called, and we were definitely in deep trouble. So that's my green onions story :)