Once you have self-reference, these are pretty easy to create. I'm quite fond of such sentences that use no self-reference. E.g. "is false when preceded by its

Once you have self-reference, these are pretty easy to create. I'm quite fond of such sentences that use no self-reference. E.g. "is false when preceded by its quotation" is false when preceded by its quotation. The above was, appropriately, first recorded by Willard Quine.