Good suggestions, all. There's rarely a one-fits-all answer, so you just have to keep trying until something works.
I like simple household white vinegar. Cheap, it's sold by the gallon in the mayonnaise aisle. It's a mild acid, and leaves no residue, except you might work up an appetite for a nice Cobb or Caesar.
WD-40 for sticky residue. Spray it on a paper towel first, the rub it on the affected area. (You know what I mean, you little pervs.) Naphtha, as in lighter fluid, works too, but keep it away from nitro finishes, because it'll dissolve them like paint thinner. Oops!