Singular vs plural noun after the verb "to like"

Question

I always thought that only a plural noun could follow the verb "to like" when talking about something in general, e.g. I like cars, until I came across the phrase "I like a mystery" which did not seem to suggest a preference for one mystery in particular but rather for mysteries in general.
Doing some research I found more examples where singular nouns were used after "to like" to form what appear to be general statements, here are some of them:

1a) I like a good story.
2a) I like a challenge.
3a) I like a person who knows what they want.
4a) I like a long coat.

Are the following interchangeable with the examples above?

1b) I like good stories.
2b) I like challenges.
3b) I like people who know what they want.
4b) I like long coats.

I am also wondering, which form is more common?

Answer 1

You can always use the plural form, while the singular is appropriate when you are talking about a particular kind of that category of things (a story that's good, a coat that's long). Mystery and challenge are a bit more difficult to explain - perhaps 'a situation that's mysterious' or 'a task that's challenging'.

"I like a car" would sound odd, but you could say "I like a car with comfortable seats".