Which Airport is better to fly into from the US, Manchester or Heathrow airport?

Depends... Manchester is certainly closer to the north so the drive would be shorter, but there are less # of direct flights from the US into Manchester. Most have a stopover somewhere -- the only direct flights are on BA and AA.

Took a look on Expedia for flights from JFK to both airports, and the cost seems to be roughly the same.

Heathrow has many more direct flights, but it is fairly south in England. Not sure where your destination is. I rented a car from Heathrow and drove to York in the north a few years ago, and the drive took ~5 hours. Heathrow is outside central London and it's right next to the M4 and M25 highways, so driving is convenient.

Hope that helps.

Stay away from Heathrow unless you need to go there. If you're getting a rental car at the airport, you will have to get onto the M25 to get onto the routes going north. Nightmare! If you are just visiting the North of England, definitely go to Manchester Airport if you can.

Heathrow is in the South of England and Manchester is in the North of England.

Definitely Heathrow I would say. Manchester isn't very close to London, so unless you're planning on travelling the breadth of the country I'd say to go with the capital!

There are lots of car rental firms, Europcar is very popular. They'll be able to give you info in the airport too.

If you're going to the north of the U.K. then definitely Manchester. Its a long drive from London to the North along

very congested roads

Manchester - closer to the north and not as much hassle as Heathrow

If you're going to nothern areas of the UK then Manchester is probably the best one. London is in the south. :-)