Many years ago, we were in Hanoi in mid-March... cool and drizzly the entire time we were there - but totally charming. One day, we will go back. Then last December/Jan. we were in Saigon - I did a foodblog about that trip - that was amazing. We are already talking about a trip to the south - the Mekong area which we have not yet seen - but that would have to be in Dec/Jan because it would be too rainy during our summer vacation time.
ETA - we didn't even see the Dalat wine - we would have love to have tried it!