Remove nicotine discolouration and fatty deposits
My absolute favorite in terms of nicotine stains or fat deposits (e.g., on kitchen cabinets, computer cases, heaters, etc., etc.) is Quick'n Brite.
The stuff is not cheap in the purchase, but there is nothing that helps better against the smoke deposits.
I take a cheap sponge (rather damp), put a little bit of the stuff on it and wipe my cupboards with it in a circle. If the dirt is persistent, I let the foam act a little and then rub with a microfiber cloth.
