IMO, all the chain steakhouses are overrated - Mortons, Ruths Chris, etc.
Not all of these are fancy sit-down places, but as far as the food itself goes, all are highly recommended.
Anaheim White House, Orange Hill Restaurant (technically not Anaheim, but very close), The Ranch, Roys, Okayama…
A few recs actually in Irvine:
Ja Jiaozi - Chinese dumplings
Porch & Swing - southern inspired, great cornbread
Puesto - definitely not authentic Mexican, but I love their mushroom taco
Angelina’s - Neapolitan style pizza. One of 3 pizzerias in OC approved by Italy’s Vera Pizza Napoletana…