I should probably mention that I'm on a quest for the best fish taco. Like most quests, this one has a certain pointlessness and an indeterminate end date. What it means is that when someone offers a fish taco on their menu, I usually try it. So far, I've been pretty disappointed (but not deterred). Most restaurants either have good fish (McGrath's or Magleby's) or good tacos (the now defunct Rosa's), but rarely do you find both. The best I've found is at the Lone Star Taqueria, a Cottonwood Heights legend, but more on that another day.
The best "fast food" fish taco I've found is at Rubios, which has finally returned to Utah Valley. Rubio's began in 1983 as a walk-up taco stand. It was started by Ralph and Ray Rubio in San Diego, CA. As a young man Ralph Rubio had enjoyed fish tacos on his frequent trips to San Felipe in Baja. Provo used to have a Rubio's at the current site of L&L, but when it closed, I had to travel to the Rubio's at 700 East between 300/400 South (by Wild Oats). Now Rubio's has opened at the Meadows in American Fork (just off the Main Street exit). I have to admit that I've been spoiled by some of the better tacos I've had. Sometimes, the Rubio's taco does taste a lot like a big fish stick. It can depend on how well it has been deep fried and how carefully it has been assembled. Remember this is fast food. The Chili-Lime Salmon taco offers a bit of an upgrade, and they also offer a Mahi Mahi taco. (Mahi Mahi sounds a lot more exotic and appetizing than "dolphin fish.") I actually liked the Rubios Carnitas taco best of all. (Perhaps a new quest?) It comes with a really good chimichurri sauce (which is more Argentina than Baja, but it still tastes good).
At their grand opening, Rubio's offered a year's supply of tacos to the first 50 people in the door. Unfortunately, I had to work that day, or we would be "livin' large."
Rubio's is part of the "Fresh Mex" movement that I usually associate with California but that can now be found throughout the country: Rubio's, Bajio, Cafe Rio, Costa Vida, Chevy's (no longer in Utah), Baja Fresh, Qdoba, Taco del Mar, Barbacoa, and Chipotle. If you want some Sonoran food (by way of contrast), try Mi Ranchito at one of its several locations. (But even Mi Ranchito has adjusted its menu to be a little more "Fresh Mex.")