Good — and bad! — science appears in many, many places, not just in the top journals. Richard Smith, former editor of the top-rank medical journal BMJ, writes:
The world also seems unaware that it is scientifically dangerous to read only the “top journals”. As Neal Young and others have argued, the “top journals” publish the sexy stuff. (10) The unglamorous is published elsewhere or not at all, and yet the evidence comprises both the glamorous and the unglamorous.
The naïve concept that the “top journals” publish the important stuff and the lesser journals the unimportant is simply false. People who do systematic reviews know this well. Anybody reading only the “top journals” receives a distorted view of the world.
BONUS: His essay also points out some of the failings of the peer-review system.