For me one of the interesting place to visit in Ho Chi Minh City is Mekong River Delta. Mekong River is on of the longest in the world and it pass several countries such as Thailand and Cambodia before reaching Vietnam.
The river cruise is quite affordable and if I am not mistaken it cost you 100,000 Dong for 3 to 4 hours tour. You will be given opportunity to visit bee farm, coconut sweet factory, fruit orchard and many others.
The best time to travel here is between December to March as the monsoon seasoned ended in December and the weather is quite windy and cold. After March the weather is hotter and drier.
Anyway enjoy the picture