It's October in this baseball-obsessed city, and for one final game, at least, the Mets are the only show in town. But what about the food? The Gobbler (whose sad fate it was to grow up rooting for the Washington Senators) made his way out to Shea Stadium the other evening for one of the recent playoff games. It's good to go to a ball game, of course. But the real purpose of the visit was to overdose on foot-long hot dogs (by Nathan's), to drown in tepid buckets of Bud Lite, to addle himself with withered chicken tenders and $8.50 containers of "Nacho Supreme."