UK or US passport when traveling to the US

This Xmas we will be traveling to the US for the holidays. The new baby and I will have both a UK and US passport and my husband only has a UK. When traveling to the US do you suggest traveling over and back on the US passports (or is it required). We will fly in to Philly and off the citizen lines are shorter. Also in the past seems he's throw doesn't mind is flying back and queuing in the UK line with my husband.

Going to the US you have to use a US passport if you're a US citizen.  They've always been happy for my UK citizen wife to go through with me in the US citizen line.

Coming back to the UK I always just ask whoever is directing traffic which line they'd like us to use, and haven't had any trouble.

It is illegal for a US citizen to enter the US on a foreign passport (the US does not 'recognise' dual citizenship so to them you are a US citizen only), so as camascato said, you must use your US passports to enter.

If you all have UK passports when you return to the UK you will go through the EU passport holder queue.

Enter each country on the passport of that country.

Not sure if you should leave on the same passport of the country or should leave on the one you are going to enter at other end though!

You have to leave the US on your US passport.  Since the airlines in the UK ask if you have a visa or ESTA when you leave the UK, you need to leave the UK on your US passport as well because you can't get an ESTA if you are a US citizen.

I just use my US passport except when I arrive in the UK and then I zip through the EU line on my return.

As noted above, if you are a US citizen then you must fly into the US using a US Passport.  London's Mayor, Boris Johnson, once attempted to fly to Mexico via Houston with his family, but since his place of birth is listed on his passport as New York, he was asked at check-in if he had ever held a US passport and when he said yes but that was a long time ago he was not allowed to board the aircraft and had to travel via Madrid while his wife and children went via Houston on their already paid for tickets.

http://www.boris-johnson.com/2006/08/29/american-passport/

You have to leave the US on your US passport.  Since the airlines in the UK ask if you have a visa or ESTA when you leave the UK, you need to leave the UK on your US passport as well because you can't get an ESTA if you are a US citizen.

I just use my US passport except when I arrive in the UK and then I zip through the EU line on my return.

Sort of clears up something that was puzzling me. DW is yet to apply for her citizenship so it doesn't apply yet. But what confuses me is that often when booking tickets it asks for your passport details. I guess if you are leaving on the US passport in both countries then it's not really an issue because you just put your US details in.

That's what I do.

thanks for all the feedback!