Long Beach has a genuinely good restaurant scene that reflects its demographics — one of the most ethnically diverse cities in the US. The Cambodian community in particular has made a lasting mark on the food landscape, and the city has some of the best Cambodian food outside of Southeast Asia.
Phnom Penh Noodle Shack on Atlantic Avenue is one of the landmarks — a cramped, no-nonsense restaurant that has been feeding the Cambodian community for decades. The num banh chok (Khmer noodles with fish curry broth) and lort cha (stir-fried rice noodles) are the things to order.
Michael's on Naples is the upscale choice for Italian food, with a terrace on the Naples canal. It's expensive but the pasta is made in-house and the setting is unique in the city.
The stretch of 2nd Street in Belmont Shore has the highest concentration of restaurants and works for casual browsing — there's Mexican, Japanese, Thai, and American food within a few blocks of each other. Rock Bottom Restaurant & Brewery has a serviceable brewpub menu and is one of the more reliable options on the strip.
For tacos, the strip of trucks and small restaurants along Anaheim Street in the Cambodian-Latino neighbourhood near Pacific is the real thing — $2-3 tacos, excellent al pastor, open until 2am on weekends.