The first area most tourists will see is District 1, Central Saigon, the financial centre of HCMC, shaped like a mirrored L it stretches east and eastward from the chaotic backpacker area around Pham Ngu Lao and Bui Vien street to the posh area around the 68 floors tall Bitexco Financial tower and northwards to the Jade Emperor Pagoda.
The area around Bitexco and the Opera House is dominated by international franchises and high end brands - Versace, Top Shop, Starbucks and many more are all well represented. You get a feeling of being in a generic rich area of any major international city, but there are interesting spots like the Opera, the rooftop bar of the Caravelle and especially the spectacular 360 degree view from the bar at the 52nd floor of the tower.
Bui Vien is reminiscent of Bangkok's Khao San Road, full of tacky bars and cheap hostels and hotels catering to wastern tourists, but also has a few gems - truly nice restaurants and places to stay, right in the middle of the chaos. A fair share of Vietnamese travellers also stay in this area, and the narrow alleyways are full of guest houses and little shops. Even though it is very intense, it is very central and a convenient spot to stay for easy access to most sights.