Good eats downtown?
My favorites are Drago Centro and Water Grill. Additionally there are many good sushi restaurants in Little Tokyo, including Sushi Gen, Sushi Go 55, Hama, and and R23. Some other good bets for lunch and dinner are Lazy Ox, Baco Mercat, Rivera, and Mo Chica.
I've never had a bad lunch at Cafe Pinot, which has the best outdoor seating downtown. WP24 is worth a try: I liked it in my one visit, but most reviews tend to be negative. Wurstkuche is enjoyable for sausages, fries, and beers. Mendocino Farms offers good sandwiches and salad-type dishes for lunch.
Other restaurants that are at least worth trying: Patina, Church and State, Chaya, Bottega Louie, Border Grill, Colori Kitchen, and Industriel. More downscale, there are some decent eats at Blue Cow, Industriel, Blossom, George's Greek Cafe, and Ocho.
Spring for Coffee is the place to go for pourover coffee and espresso drinks. Sustain Juicery has fantastic juices and smoothies, which I often drink for lunch.
As you might imagine that is a familiar subject here as evidenced by the sheer number of discussions you can find with the search function. Just as a (small) example you can read through some of these for dining ideas: