seems like its all been covered but ill add. fireworks. drinking games ( some kind of spin round a stick then run forwards is always class) if you can get a dj thats always good, but sometimes tunes in the background are better to let you talk. i would say a shit load of beer in a huge tub full of beer. somekind of industrial strength spirit that you can shot for when it gets a bit later. if your yard is big enough a fire pit.

and finnaly if you got the cash STRIPPERS

have a good one mate

peace