Organise your own stag do or let an organiser do it for you

A stag weekend is undoubtedly a great event but it can also be a great pain in the arse. If you do it yourself you can create something completely unique that's far better than anything anyone's been on before and you can also save everyone who goes a few quid. What kind of stag do you think works best - a pre-organised event or one that's organised by the best man?