I used to hate them, too, but now the DSs are 10 and 12, it's fine. The 12 y.o. doesn't bring his mates indoors (which is a bit of a pity as it means I can't size them up!)- and the 10 yo's mates are now of an age where they play nerf wars, lego or the Wii. Or head out on bikes.
One small incident recently: my bedroom is out of bounds, but a week ago I went to get something out of my blanket box- and found the base of it was broken. Turns out one of DS2's mates (who is a boisterous but generally good boy) had gone to hide in it during a nerf battle and of course, the base didn't take his weight. I was very unimpressed that DS2 didn't own up at the time but am realistic enough to recognise the boy concerned wouldn't have. I did wonder on the day why he suddenly announced he had to go home...
And 'a funny'. We moved house and school 2 years ago, but not far. DS2, then 8, wanted to keep contact with an old school friend. I know this lad's parents quite well (we socialise from time to time) and the boy, though a bit 'odd', is fine. The issue was always his precocious, spoiled, whiny little sister- the reason DS2 stopped wanting to go on playdate to his friend's house as they were always forced to let her join in with everything (and dominate, and scream when she didn't 'win'). Anyway, 'M' came over. Normally, by the age of 8, I could leave my DSs and their playdate to 'get on with it', unsupervised. But M's polite if a bit 'persistent'. He was desperate to play out in the Close, which was fine, but he only wanted to play cricket, not appropriate on a road with dozens of windows facing AND not a huge amount of fun, so my DSs came indoors to play the Wii. M came reluctantly in too, but in no time was down again (3 storey townhouse) complaining to me ('Mrs P!, Mrs P!') that DS2 wouldn't 'play with me, and I'm the guest and my mum says guests should get first choice' (which, to be fair, is sort of fair enough. DS2 was always indulged at M's house except for the 'annoying little sister aspect!). SO I called my 2 down and said Come on, play nicely with M, to which DS2 said (privately) 'But he's boring! All he wants to do is play cricket which we can't', so I bribed DS2 to play with M (I am keen to keep things sweet with M's mum as she's a friend and it's embarrassing when a playdate goes wrong!), DS2 agreed, so I said to M 'OK, what would YOU like to play that isn't cricket?' and he said...
'Victorian school rooms, and can we dress up?''
...enough of your parents' private life, I said 