Like the Jacko inquiry, there are many questions to be answered: Should you invite the stag's coworkers, or will that mean he can’t let his hair down as much as he might like for fear of career-ending repercussions involving a fire extinguisher and a horse tattoo? Should you invite the father of the bride and/or groom to keep them sweet, or will they suck the life out of it with their weak grasp of popular culture and old, old memories?
What about the guys that he isn’t really that fond of but feels obliged to include, like the socially inept cousin? It's simple, just stick to this one golden rule: You can always have an extra simple night at the stag's local which can include all his B-list mates. How much to spend on the stag do obviously depends how well off you are as a group.
Not the, "yeah he's kind of alright and I've known him for years" man.
Not the "actually he can be a bit of a dick sometimes but I can't trust anyone else not to get me arrested" man. So, if you're organizing a stag do, you need to be absolutely the best man and organize the stag do to end all stag dos.
Similarly, if it’s just you and the stag, fruitlessly chasing each other around a vast paintballing field for three hours will only serve to highlight your tragic loneliness.