I make an annual pilgrimage to Jim's on South Street in Philadelphia. It is amazing. That perfect grilled w/ a little steam lean meat on excellent sub rolls. I have yet to find an LA cheesesteak that can ably fill my cravings until next year.
I've tried three places in LA so far:
-Philly West does a fair job. I find the bread too chewy.
-Under Over Sports Grill in Santa Monica was a disaster, despite advertising "the best cheesesteak in town". Ugh, chewy meat with tough lines of gristle that I could barely get through. Stay Away!
-Philadelphia Sandwiches in North Hollywood, while they tried hard, just didn't work out. Onion wasn't cooked enough, chunks a bit too big, something else I'm forgetting.
Where do you recommend?