bar Allez Boo! good ambiance, good music, good fun

There are a lot of fancy clubs, but watch out for police raids in the 'Apocalypse now' club..They take everyone with them for questioning, and nobody likes communist prison.

La Cantina: a great little mexican restaurant, run by Tanh, a really nice guy. We spent one week in HCM City and had many fantastic nights out with the people working there.

... et je gagne le coeur du monde !

Bring some cool evening cloths

dont miss nightlife and the tunnels of vietnam war near ho chi minh

One of the places I would recommend with no reservations, Ho Chi Minh City is a sight to see, with a bustling nightlife, great (and cheap) delicacies, a well-preserved culture, and for you history junkies out there, many war remnants.
Cu Chi Tunnel is a must. It is located in the suburbs of the city, but easy to get to nonetheless since cab fare is so cheap. There are deserted tanks, and anyone is allowed to fire live rounds from a real M16 if they pay a little out of their pocket (a few USD, not over 10).
The nightlife is great too. Pha mu lau (not quite sure how to spell it, my apologies) is a great place for cheap drinks, so is Eden, located adjacent to it. Bounce is a good hiphop club and has impeccable western furnishings. Other than that, there is shopping at Diamond Plaza during the day, which also boasts an accessible bowling alley.