Favorite city in Vietnam?

Nha Trang
Besides Ho Chi Minh, where in Vietnam is your favorite area to spend your time?

I know Ho Chi Minh is the big city with everything happening, but I would prefer to save some money and live somewhere else in Vietnam.

I have been in Nha Trang for the last month, and it's time for me to move on. I love Vietnam, but where is the best place in Vietnam to spend 2-3 months?