I sure wasn't impressed with Pastrami Queen in NYC -- there is somewhere in the NYC forum a lengthy thread on NYC delis.
There are a bunch of decent delis in LA. I like the chain Jerry's Famous (Solly's in Van Nuys is under the same management). Also Art's in Studio City, whose slogan is "every sandwich, a work of Art." Art clearly eats his own food! A lot of folks like Nate and Al's too.