Ponsonby Road is Auckland's most reliably enjoyable street for an evening out. The cafes that line it during the day transition to wine bars and restaurants after dark, and the pedestrian traffic keeps going well past midnight on weekends. The crowd is mixed — locals from the surrounding Victorian villas, visitors who've heard the reputation — but the feel is relaxed rather than flashy.
The best approach is to walk the length of the road and pick what looks good: there are few bad choices, and the concentration of options means you can graze across several places in one evening.