Reply #3: Much depends on the handling history of the bottles

[BrewerJohn]

Once I came upon an outdated 6-pack of Fuller's ESB (a true treat of a
thoroughbred English ale) at a considerable markdown in my local
liquor store. The clerk basically gave it to me for free (I think I
had to pay bottle deposit and tax) because he felt guilty selling
me beer that was bound to be stale--it was a few months past the
"best-by" date. That sixer was totally delicious. Later, I bought
some bottles of the same beer that were well within date at the same
store. Those were definitely stale, a mere shell of the greatness
that is Fuller's.

Especially for imports, but applicable to all--rough handling, exposure
to light, and extreme temperature changes during shipping and storage
make a huge difference. Proceed with caution!