This research was carried out by the simple expedient of doing a Google search for "answer to notting hill". This technique can, of course, be extended to finding equivalents for other iconic districts: for example, Camden Town apparently has equivalents in Tokyo's Harajuku, San Francisco's Haight Ashbury (so that's full of brightly-coloured teenagers and mohician punks with "PUNK" in big letters on their clothing?), Stockholm's Hornstull and Buenos Aires' San Telmo. Running it for Melbourne locales was less fruitful; there are apparently no Brunswick Street equivalents anywhere, though there is one Chapel Street equivalent (Geelong's Packington Street).
Incidentally, there is no Melbourne equivalent of Notting Hill listed. Melbourne does have a locale named Notting Hill, but it is a rather desolate stretch of urban sprawl north of Monash University, where there are enough industrial estates to keep the student-infested 1970s bungalows spread out. Perhaps Carlton or Williamstown would be a more accurate equivalent?
Geelong's Pakington Street is nothing like Chapel Street. The Geelong West end has more in common with Lygon Street in Carlton while the other end of it in Newtown is closed to say High Street, Armadale.
Searching for such a phrase surely subjects you to the pufferies of Real Estate Agents and chintzy lifestyle/PR reports from local rags, er, community newspapers...
San Telmo in Buenos Aires is a lot cooler and grittier than Camden Town and there is a conspicous absence of wankers wearing leather jackets with PUNK written on the back. Argentinian punks don't need to advertise, it's pretty obvious what they are and Porteños, as they call themselves, don't buy into that retro bullshit that seems to afflict so many post wannabes in Pommielandia.
The only comparison I would make between San Telmo and Camden Town is the markets, with the San Telmo ones being infinitely more interesting and the grass cheaper.