The original Channel 5 version of Fort Boyard in Britain had them, illustrating what games were going to be played in the next segment. It always infuriated me to an irrational extent - part of the fun of lots-of-little-games shows is not knowing what's going to come up next and enjoying the surprises as they are announced. In-show spoiler announcements are an instant way to cuss me bad. (Happily, Challenge ?'s new version of FB does not. CHALLENGE WINS.)
My favouite bumper-like entity credit must go to Interceptor, which is one continuous forty-minute game with no natural breaks in the action within. They simply have a dramatic shot of the action, particularly a long-distance one illustrating a surprise that a contestant is about to receive, then freeze-frame, "end of part one", musical stab, break, musical stab, "part two", unfreeze and go again.
Incidentally, I came mighty close to posting "Hello. I have had a US game show theme running through my head all day. Please someone post a phone number so I can ring you up, sing a bit of it down the 'phone to you and you can tell me what it is", but I finally found it on my computer to solve the mystery. (It was the 1980 To Tell The Truth theme - specifically, all of it from the piccolo part onwards, for what it's worth.)
Grr, arg
Chris