In message , Mike
writes

Greetings from across the pond...

Heading from Gatwick Airport to Liverpool in a few weeks. Not renting a
car. Followed by a week in London. What's the [ quickest / easiest /
cheapest ] way of getting from Gatwick to Liverpool?

I doubt that anyone is going to have the time to give you full details
of all three of "quickest, easiest and cheapest" - the cheapest is
likely to be the longest, and so on.

I would certainly consider flying on from Gatwick to Manchester, which
takes about an hour (so is undoubtedly the quickest route). From
Manchester Airport there are good and quick train and coach services
into Liverpool - if there are two or three of you with luggage, a taxi
is another possibility (about 50 pounds).

--
Paul Terry