Not many as I've never been a soft touch and have also never asked for anything I wasn't willing to pay for. Also never had money to 'lend' as that means giving it. If I don't have it to give then I don't lend it, either. You just say, 'No, I'm not able to do that.'
One group of flatmates at uni I ended up having to buy a small fridge for my room due to flatmates nicking so much (and keep my food in my room).
We once bought a house from a man who'd inherited it from his mother. He'd never lived in it but had been using it as a postal address whilst he worked abroad. Fair enough.
Bought the house, kept getting post for him, return to sender, return to sender.
He showed up one evening and knocked on the door about 6 weeks later. Opened up to him asking for his post. Told him we'd been returning it to sender. He went ballistic! We were supposed to keep his post and every now and again he'd come and get it. He was wanting to 'have a look' in the house, too, see what we'd done to 'his mother's' house.
Told him to get to fuck, we're not his fucking secretaries, it's our house not his ma's and if he came back again we'd ring the police.
Dickhead. Never heard from him again.