Oh, I've got a great one.
Survive for 30 days to win a grand prize of one billion dollars.
Each celebrity is declared an "enemy of the state" and is given a 12-hour head start before the "Hunters" (or "Stalkers") are released to catch them.
The contestant earns £100 per hour they remain alive and avoid capture. An additional £100 is awarded for each Hunter or law enforcement officer they defeat.
The contestant is given a cash sum, a pocket video camera, and is required to send in two video messages to the "Games Network" each day.
If the contestant fails to send the daily video messages, they are considered to have defaulted on the contract and stop accumulating prize money but they will still be hunted.
I'd give the hunters some interesting tools. And when if we run out of the usual slebs, I'd pick people who have made the news for some reason. And maybe jazz it up with some jeopardy if the viewing figures declined. Got to keep it fresh and exciting, after all.
A name? Ummm, maybe 'The Running Man'?