Stag Do...actually Stag Don't.

The great thing about youth is that you're either so drunk the whole time or so completely emotionally incomplete, that not only do you find traffic cones hilarious, you're convinced other people will find stories about them equally rib tickling. This usually doesn't make any difference to your life, as the worst that can happen is you'll recount the time Binky shoved his underpants on his head and sang the National Anthem in the middle of the street, to your girlfriend's granny at Sunday lunch, and she couldn't hear anyway.
Drinking is fun. In may ways, when it's not involving imbibing floor cleaner and cough medicine, it's an effective social lubricant that can get even the most challenging of characters to have a good time, and in some cases even a girlfriend. But when it comes to horrific modern day crimes, there are few worse in this world than being made to listen to other peoples' drinking stories...especially when they're crap. Real drinking stories that start off in one continent and end in another, without any recollection of the marching band you temporarily joined are all well and good. The ones where you simply drank your own bodyweight in Sangria and woke up naked in the beach are OK if you were there, but as a story really don't go anywhere - we've all woken up naked at some point without any real idea of the details.
So many times I'm asked if I can include the Stag Do/Bachelor Weekend events in the Best Man Speech, and to be honest I'd rather drink a cold cup of sick. OK its your speech, I'm happy to fit in with whatever you want, but there's nothing more boorish, exclusive and dull than hearing a Massive Big Up to the Stag crowd, especially 'Tommo' who was the last to take his pants off his head upon the return to Stansted airport. As Best Man your job is to make everyone laugh and by selecting a specific target subset you're completely failing to do that. But it's not specifically the exclusivity that I have an issue with, neither is it the dullness of the anecdote...it's the fact that it's not about the groom.
The speech should only ever be about the groom - not about the venue, God forbid the catering, 'being The Best Man', or the bridesmaids...so when when you start talking about the antics on the stag weekend you're doing what so many Best Men are tempted to do: you're really talking about yourself. As soon as the spotlight diverts from the Groom and his lovely wife, you're completely missing the point. You only have a very limited time to hit you mark in the speech and so talking about the Stag weekend is just taking up valuable space, and at the very least is more than a little conceited. The worst thing a Best Man can do is convince himself that just a little bit of the day is about him. It's not. You're there to entertain, and make 'em laugh, and turning it into a pub type drinking story fest with the odd bit of nudity thrown in, never works.
My advice is to strip out the detail of that anecdote and use it as a punchline to a much more general and amusing observation about the groom's behaviour. To be honest it's a bit hard to explain, but as a rule if you're trying to tell somebody how hilarious something was, rather than say something funny yourself...you've got it wrong.