h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Like many things there are good examples and bad ones. American and british Sci-fi have alot going for them. Although there is a tendancy in american Sci-fi to have alot of SFX i wouldnt say they rely on it. X-files uses very little but has a plot intricasy that is un-rivaled.
the old brithish Sci-fi like Blakes7 and Dr Who Is cult for different reasons. the shakey set add to the appeal because it doesnt matter.

As a fan of both the 'shakey sets' shows you mention I must demur. Okay, being a low budget TV show is written into Dr Who's DNA, but even so there were occasions when it achieved very high production values wihtout losing its appeal (and the number of times I've seen the sets vibrate in colour episodes is tiny, this is just one of those apocryphal things everyone goes on about).

Nearly all these cult shows are cult because they're imaginatively written and reasonably well-acted, and they take place in a fictional universe with enough depth to be immersive if you're that way inclined - i.e. you can learn Klingon or write theses on Dalek history if you so wish. A lot of fans of these shows are the kinds of people who are usually socially marginalised, and being that far into a show gives them a sense of belonging and also of superiority, from knowing stuff and getting references that the casual viewer wouldn't.

Every time someone suggests that a putative Dr Who revival should discard the 40 years of continuity already established, and start over from scratch (thus putting the die-hard fan and the casual viewer on a level pegging as far as knowledge of the show is concerned) the reaction from big chunks of fandom tends towards the hysterical, arguably for this very reason...