My personal fave is the collection calls I get. Most of them come up on the CID as "Toll Free Call"
Now my wife and I have our last name and first initials in the phonebook. I get collection calls for every first name in the book (hilarious) although one from a company called DRS was actually for my name. Cue Nancy! (the former employee that apparently recorded the message)
Hmm, curious (because I haven't missed a bill in over 15 years, much less left one delinquent) I took the call. Asking for this and that, and I refused to give them my information (I don't give my SSN out to anyone, tough luck) and finally get them to say they were looking for payment on a bill for such and such address. The problem was the dates. They were looking for bill payment on something that was ~5 years after I moved from there. I did not tell them this. After looking up the company online I had found they were one step from full blown scammers. I simply told them it was obviously past SOL (cue the "you're scum" "deadbeat" "pay your bills" chants) and if they believed I owed them the money to sue me. I also informed them to forward all future correspondence to my attorney (Mr. X) at X, Y, & Z law firm oh, and this is Wisconsin, so I've recorded the whole call. Oh, and your bosses can expect a letter from my attorney informing you of all the legal niceties. Yes, I did have my attorney send the letter.
I haven't heard from them again. In fact my telemarketing calls (in particular the debt collection calls for James, Jessica, Jonathon, Jim, et al.) have dropped as well.