Though I didn't read every last post, I'm quite impressed by the diversity of opinion here.
The people I game with are definitely the drinky sort. Of course, that goes for at the table as well as away from it, so we can all hold our alcohol pretty well. There are some sessions where everyone stays relatively sober, and that's fun. There are some sessions where everyone gets tanked, and that's fun too. Sure I've seen it lead to droopy eyelids (though never outright misbehavior), but I could say the same about the guy who always woke up at 4AM.
What I think is especially cool, though, is that table dynamics largely determine how much drinking is going on. It becomes obvious early on what kind of mood everyone is in, and intoxication levels follow the mood. Is it going to be a joke filled, "remember that time when we were all playing liches...", endless pop-culture quoting sort of session? Or is it going to be a serious, never getting out of character, tactics like a well-oiled machine session? (Incidentally, I've seen both done quite well sober & smashed). Maybe it's because we're all so close and such good friends, but I'm consistently impressed at how the table tends to function as a whole.
Though I'm a smoker (as are most of the others I play with), I don't much care for cigarettes at the table. I like taking a break before/after combat, stepping outside, and chatting with friends that I don't get to see as often as I'd like. Sometimes it's about the game, sometimes not. Either way, I think we all come back to the table a bit more clear-headed, ready to game.
The guy I've been gaming with longest smokes some excellent pipe tobacco at the table, but I love that smell. So it's all good.
As far as "other" pipes go... I find that to be a bit distracting. Lost trains of thought and what not. Especially for the DM. A little is fine, but I've seen it take a much bigger toll on a table than alcohol ever has.
My two cents. Like I said, quite the diversity of opinion.