i generally use metho on a rag as a first step as you want an alchohol based product to evaporate off.  For really stubborn stuff, put metho on magic erasers (available in woolies/hardware etc), and scrub lightly - these are like superfine sandpaper, so can eat through artwork, but if you are careful are great to get rid of marks.

After metho, then i polish with Novus 2, and wax with Meguairs Carnuba wax.

Really, to clean properly, you need to pull most of the stuff (ramps, plastics etc) off the playfield, as areas you can't get to will just make the playfield dirty again very quickly.  Also remember to pull any ramps off underneath the playfield and clean them.

Look through some of the restoration threads on here to look at other peoples methods (just avoid looking at El Timbo's ones as you will get disheartened looking at how awesome his restorations are!)