I had ridiculously enthusiastic one approach me noticing I was carying a Waterstones bag and started trying to engage me in conversation by asking me if i'd bought any interesting books. I told her in no uncertain terms to mind her own fucking business.
Also, a good line to use on the ones who ask if you've "had any accidents or injuries in the last few years?" is "fook off, I've always looked like this!"
speaking of which, who in their right mind thinks "ooh, yes, now you mention it, i have had an accident. I would have never have thought of claiming compensation if you hadn't of asked. I mean, you never see this sort of service advertised on TV or in the papers or anything" and then lets some dodgy looking character decked out in the latest primark shirt and tie combo take all your personal details.