As for anyone wondering which franchise to test out if they loved NY, I'd say either go for the first three seasons of Beverly Hills, or all of Vancouver (it's only two seasons long). But there are so many stand-out eras in each of the franchises.
I'd gone a long time watching all of the US ones aside from OC, as it seemed like there was just so much of it to catch up on. But I finally started it about 18 months ago and am now up to season 10 - the notorious cancergate season. It's been a ride, but totally worth it. The Gretchen and Alexis years, the reign of Heather, the start of the Shannon era, and now Vicki defending Brooks' cancer faking. I think it's special amongst the franchises because not a single member of the cast of any given season is likeable. All absolutely awful people. And compelling viewing, as a result.