Growing up in Vegas I feel like Mexican places that serve plate meals are engraved in my veins. I grew up on Roberto's, but now only have it when I'm drunk or hung over. I usually get my Mexican food fix from my best friend's family nowadays.
Viva El Taco has the same concept of a Roberto's but it just taste better in my opinion. They have all your tacos, burritos, and plate combos. Viva also has some of the most solid street tacos in Vegas. When I say solid I am referring to their consistency and ability to satisfy a taco craving lol The Freshness, flavor, and convenience factors are there. They even ask if you want your tripas crispy or soft which is my gold standard of taco eating lol Their tripas and tongue are my recommendations for tacos.
I'm all for waiting for good food, but It's seriously so nice being up the street from a good taco place where I don't have to wait in a huge line. Their salsa bar is also always cleaned, stocked, and looking fresh and full. I also dig that their staff is pleasant and actually look happy to be at work. Given their quick service, affordable prices, and store upkeep I don't have any criticism. Just a solid little Mexican joint.