[Neil Jones]

First post back in ages and got a wee silly question from following along:

What is the longest gap between an episode of a gameshow being filmed to it being aired? Sorry to ask.

Couple of open ended contenders for which the gap between filming and broadcasting grows longer every day:
Press Ganged (filmed in 2004 and then was never aired - why was never disclosed)
Man Versus Beast (scheduled for 2003 and was then pulled).

As for stuff that did get aired...
There were those episodes of 2007 Supermarket Sweep that ITV didn't air and they ended up debuting on Challenge two or three years later. This happened with another show as well, but I can't remember what it was, it might have been Joe Pasquale's Price is Right.

According to to One Question Shootout there's a few Series 14 episodes of The Chase that haven't appeared yet, best part of two and a half years down the line.