I went to NYC last month and visited Joe's. Honestly I like the options out in San Gabriel Valley much better. Although I've only been to Din Tai Fung for xlb, Joe's dumplings are huge, much too doughy, and the soup is not as flavorful and too greasy. In contrast, Din Tai Fung's xlb are much smaller and delicate. I guess it's personal preference. IMHO, Asian cuisine in California is much more authentic than NYC, given it's a shorter distance to the West coast vs East coast from the motherland.
you are not off. joe's shanghai in nyc has dramatically gone downhill within the last 4-5 years, due to tourism and national hype. as bad as it has gotten, sadly, it's still among some of the better options for XLB in ny. but i would recommend avoiding the manhattan branches (or chinese food altogether) and head for flushing.
I haven't been to Joe's, but if you're craving the kind of XLB that are impossibly small, delicate, and bursting w/ meat juice (i.e, the ones that are made in Shanghai), then I've never found anything like it in the LA area. The ones at JJ and Mei Long are much bigger and more clumsily made, and the ones at DTF lack the juiciness. I've resorted to making my own as a result.....
Avoiding the "best" XLB question, but still trying to answer your query.
There really isn't an LA equivalent of the Joe's style XLB. The closest you'll find is J&J (or Jin Jiang) in San Gabriel.
The LA equivalent of Joe's in terms of XLB notoriety and fame would be Din Tai Fung, but be warned, the style of XLB at Din Tai Fung is no where close to what Joe's dishes out. Not saying one is necessarily better than the other, but the two are different. Sort of like going to McDonald's and ordering a Big Mac and expecting a sirloin burger -- gonna be rather disappointed.
As an aside, in my opinion, the best thing to get at Joe's is the braised pork shoulder. Give me a plate of that and some rice and I can die a happy chowhound ...
Jin Jiang, Mei Long Village, and Din Tai Fung are 3 of the top places to start at.
Jin Jiang and Mei Long Village are both in the same shopping complex, so you could try both of them one right after another.
Din Tai Fung Restaurant
1108 S Baldwin Ave, Arcadia, CA 91007
Jin Jiang Restaurant
109 W Valley Blvd, San Gabriel, CA 91776
Mei Long Village
301 W Valley Blvd Ste 112, San Gabriel, CA 91776