I found the best cleaner for my glass cook top. I'm always scared of scratching it, so it stays kind of dirty usually. I found this Scotch Brite Cook Top Cleaner, which is a plastic handle and refill pads. The pads have the cleaning solution already on them, and they are the appropriate scratchiness level for the glass. It leaves the cook top  sparkling clean and you throw away the pad. Not great for the earth, since the pad gets thrown out, and you also have to wipe away the excess cleaning solution with a paper towel, but if you use it only occassionally, your cook top will be beautiful. Tip: buy the refills at the same time as the starter kit to avoid having to search around for them.