Exotic Street Food: Balut
Most Filipino people love to eat this with beer but it's not only popular in the Philippines but in other southeast asian countries too. I remember particularly that every time I visit Cambodia, I'd see people selling this on the street too. According to wikipedia, this is also available in Laos, Thailand, Cambodia and Vietnam. However, I have never ever seen this being sold in Thailand, probably because I stayed in Bangkok and not in the province.
Eating this can be controversial due to religious and health reasons.