I usually associate the Thames opening screen with Benny Hill myself.

I think Ron Grainer and Dudley Simpson scored just about every British sci-fi show of the 70s.

The only show I religiously watched as a child and pretty much the only show I regularly watched on Nickelodeon as a kid (surely I can't be the only one who remember's Nick's early 80s "Third Eye" block of weird, British sci-fi programming)

I got a few of these boxsets and the show holds up surprisingly well. Sort of a slightly kiddified Doctor Who, for lack of a better description. There's a few complete serials on YouTube.

I remember seeing this show on Nick a few times. There was a part where the scene switched to America, and they illustrated this by showing a man dressed as Uncle Sam walking down the street holding red, white and blue balloons. Had I been a bit older, I would have recognized how awesome that was.

I remember I caught a piece of the 1990s remake they did and thought that it was the coolest thing ever. I look at this opening and realize I was sadly mistaken.