"Unfortunately Marylebone is utterly pointless because it's on the tube to precisely nowhere important. You have to change lines to get anywhere."
fortunately, most of us are blessed with legs, so after arriving at marylebone overland, can take the very short walk to baker street tube, and thus access the hammersmith & city, metropolitan and circle lines, should your target destination not be on the bakerloo line.
there are so many towns of a commutable distance to london, that making a recommendation is nigh impossible without knowing more about the OP's target destination(s) for commuting in london - which would be the overland station you would want to arrive at?
i've lived in surrey, kent, and now buckinghamshire, all of which have towns which fit the bill - but it does hugely depend on where you will be regularly travelling to. in my opinion, oxford, cambridge, guildford, st albans, sevenoaks, beaconsfield, to name but a few, would all meet your criteria.
as i currently live in bucks, i'm very biased, but am delighted with the schooling system, and (provided they arent disbanded) the possible opportunity to have access the the grammar school system in due course.
plane noise has never been an issue for any of the places i've lived, and seems rather more relevant to west london, and a straight line out from west london along the M4, perhaps as far as bray.
i wouldn't really consider harrow to be an "escape from london"!