Orange County is a hot spot for Ramen, especially Costa Mesa, which has been referred to as Ramen City, USA. So it follows that the best place for Shoyu Ramen is there, in a tiny, cramped shopping center: Kitakata Ramen Ban Nai. The delicious noodles and broth make this place Brode's Best.
I want to mention that the same location housed another Ramen great: Kohryu. I still miss Kohryu, but Kitakata is so good that it dulls the pain of that loss.
What to Order
The Chashu ramen (pictured) and the Kitakata ramen are the same, except for the amount of pork you get. Both are delicious. I also highly recommend the pan-fried gyoza. They come with a spicy yuzu paste and very tasty dipping sauce. People have been known to enjoy the Karage here as well.