Which one would you do if you could only pick one? Asking everyone who has experienced both cities.

hanoi no question

thanks rhkkmk. What should I not miss?

Hanoi also. You should not miss Hanoikids - the free guide service will show you the whole of it.
www.hanoikidsclub.org

The beauty of Vietnam is in the people - get to know them.

Hanoi.....it's by far the best. Has tons more character.

I agree with the consensus for Hanoi--but I did really like my boat trip down the Mekong out of Saigon (HCMC). My report on both is here: http://www.fodors.com/forums/threads...p;tid=34659821
if you'd like a little more info.

Definitely Hanoi, possibly with overnight trip to Halong Bay. All of the standard sights listed in the guide books are worth seeing, but I would especially recommend spending time in the old quarter wandering around - on foot, not in a cyclo (I stay there, too). Also the Temple of Literature, and I like the statues in the Fine Arts Museum.