My parents have recently sold their house in the UK and want to give my wife and I a gift totaling 50k GBP (currently approx $80k USD!). What is the best way for them to make this gift - one lump sum wire transfer or smaller annual gifts? Or would it be more beneficial to have them make the gift into my UK bank account and then transfer it from there? My parents are not US citizens or residents. I have not declared my UK bank account to the IRS. Many thanks for your advice.

Have them transfer the money from THEIR U.K. bank account to your United States account. Do NOT put the money in any account in your name in the United Kingdom, because doing so WILL make you liable to submit an FBAR and could require reporting under FATCA.

The FBAR is required if the U.K. account exceeds $10,000 at ANY time in the calendar year.

There are no transfer taxes and no gift taxes because your parents are NOT U.S. citizens.

One lump sum wire transfer is best. If your UK account is over 10k, you should report it on the FBAR. Some advisers are concerned that a gift to a US account might trigger US gift tax.

IntlTax:
As the parents are not US citizens or residents, there would not be the need for a gift tax return as that doesn't apply to them.
The only form that might come into play is form 3520 (if the gift is more than $100000)

Nonresident aliens can be subject to US gift tax if the property is tangible property situated in the US.

Thank you all very much for the advice! I am going to organize the transfer as soon add the exchange rate is at a decent level. As I understand it, I should not have to file any paperwork as long as they do not give me more than 100k USD. I'm going to work on the basis that transferring funds into a US account is not generally regarded as 'tangible property'.

Correct! Monetary funds are NOT tangible property!

I guess it depends on what type of "monetary funds" your are referring to. The IRS has concluded that some types of monetary funds are tangible property. Thus, the risk.