On a recent episode of "The Price is Right," Eugene Byon (who a few of us are friends with) was called to come on down for the second time. This is thanks to PiR's rule allowing contestants to become eligible again after ten years.
Previously Eugene was on Millionaire, and was invited back for "Second Chance Week."
Are there other examples of a contestant making two separate appearances on two different shows? For the sake of this discussion, let's say defending champions don't count, but being invited back for a ToC or other tournament does count.