So, yes, my previous answer was, of course, fairly sarcastic but based on a lot of truth. In UK restaurants, I will generally have a quick squint at the wine list but invariably I do just order the cheapest. Needless to say, I rarely actually say "Bring me the cheapest bottle you have" but I've certainly simply pointed to the one at the top of the list before now and said "We'll have that, thanks".
I've only ever sent one bottle of wine back in my entire life - not because it was off or bad or corked, but because they were dozens of little flies floating in it.
As a general rule though, on holiday, especially in France, Spain, Greece or Italy, I will always simply order a carafe of the house wine with my meal. As yet, I've never been horribly disappointed. I always find that even if it tastes a bit nasty with the first glass, it will improve no end after the first three or four glasses!
I should probably also add that I only rarely go out to eat in the kind of restaurant where the waiters know anything about the wine other than the fact that it comes in bottles and in 3 different colours!