Thank you all for your very helpful suggestions. After a lot of thought, my husband and I have decided on Hanoi and Siem Reap for our trip next Feb. We'd like to book our international flights this weekend. But, before we do, I wanted to get your thoughts on our planned itinerary:
Overnight flight from JFK to Bkk. 1st night Bkk airport hotel. Fly out to Hanoi next morning and spend 3 nights in Hanoi. Then, on the morning of the 4th day, depart for an overnight stay on Emeraude cruise in Halong Bay. We would fly to Siem Reap upon our return from the cruise and spend 4 nights in Siem Reap before flying back to Bkk to catch our return flight home.
If everyone thinks it's absolutely necessary, we could possibly squeeze out one more day for travel. Otherwise, just want to make sure that the trip doesn't seem too rushed. Thanks for any advice!!

why go to bkk? how about untieds direct flight to VN? i think it is through CA, but wouldn't that be better?

or take one of the european carriers through europe: air france, luftansa, brit air, etc...

Bob, United's flight to VN lands in HCMC, so they would still have to take another flight to get to Hanoi.

I just returned from Hanoi and Bangkok on Thursday 5/17. I took Singapore Air non-stop EWR-SIN-HAN. You do not have to overnight and your arrival will be at about 2pm.

Taking the United flight would add a lot of travel time, as we live in NY. There was a JAL flight that we were considering which took us to Hanoi via Tokyo, but it involved about 25 hours of travel and we would have arrived in Hanoi very late at night, so we'd still be losing the day. The JFK-Bkk flight is direct and takes 18 hours, so I think we'll be happier, even if it means spending the night in Bangkok.

Baltorep- How is it a non-stop flight if it goes via SIN? How many hours of travel time was it?

I love the SQ non-stop. I have done this flight twice. Singapore has been rated as the top airline in the world for many years running. However, they only offer Business Class and Executive Economy (check out www.singaporeair.com for details on Exec Econ).

The flight schedule is as follows.

EWR-SIN 1100PM-0540AM +2days (cross int'l date line) 18.5 HRS TVL TIME

SIN-HAN 1005AM-1235PM (ONE HOUR TIME DIFFERENCE SIN-HAN) 2.5 HRS TVL TIME

Please let me know if you have any more questions.

OOPS - SIN-HAN Travel time 3.5hrs

Changi Airport is a great airport to do a layover in. Also considered best airport in the world. The new Bangkok airport is very nice as well but Changi does have free internet terminals throughout the airport.