L.A.
I just took my son to Zippity (sp) Doos in Roslyn (right off the LIE). It has all sorts of bells and whistles like sitting in a jeep or car and watching a video while they cut hair. I didn't need all that, I just wanted someone who knew how to style a kid's hair.
It's quite pricey: $24 for a haircut. My stylist did a decent job (better than a barber). It might be worth it for a girl's cut or if your child is afraid to get his/her haircut, but if you are doing a basic cut, I don't know if it's worth it. The place is very cute and they also sell toys and your kid gets a balloon when they are done.