PS probably the best one -- long lunch, that is -- I've had is at The Sportsman with their tasting menu. About 13 courses, a bottle of pop, a very nice red Burgundy, and then something sweet. Lasted about 5 or 6 hours. Sublime food.
The utter treat is a long lunch, by which I mean start at midday and keep going until you get thrown out as the evening seating starts to emerge. I do this with a few friends about once a year, always at a BYO restaurant. But it requires a day off, so what I more regularly enjoy is a long dinner...