My experiences are a few years old, so anything specific i post has a good chance of being gone now.
Krispy Kreme is always a winner, but i imagine you're looking more for food-food.
If I had to rank order the ones I'm sure still exist:
1. This one used to be off an alley right on the Strip. Now it looks like they moved to The Venetian. I imagine quite a few placed relocated due to the Formula One races needing space.
https://www.venetianlasvegas.com/dining/restaurants/smith-and-wollensky.html2. Top of the World Restaurant -- The Strat. Prices are a little high (like the view), but guests get 20% off. Both times I ate there, My San Diego project manager treated our group.
https://thestrat.com/restaurants/top-of-the-world/menu3. i always made a trip to The Hard Rock Casino each trip in part for a meal at The Pink Taco. Great food, casual dining, and very affordable. I see this link saying the Pink Taco will be opening again after being close when the Hard Rock closed.
https://igaming.org/casino-news/pink-taco-returns-in-the-continentals-las-vegas-revamp-by-2025/4. Breakfast at The California Market Street Cafe. Usually had coupons, but th food was top quality, the pancakes were tasty, and the prices seemed quite reasonable. Since I usually stayed there, it was also convenient.
https://thecal.boydgaming.com/dine/market-street-cafe#sp5. MGM Buffet. The food was good, but not to the level I'd crave. If visiting the Strip, it's a good affordable option. The few times I went, they were very busy, and the staff was not the most attentive. Pretty much self serve, so ask all your questions when you get there. They pretty much leave you to fend for yourself most of the time. If you leave hungry, it's your own fault! Compared to other popular buffets, and the fact it's at the MGM, it's hard to complain about the price.
https://mgmgrand.mgmresorts.com/en/restaurants/mgm-grand-buffet.html6. Fremont Casino's Lanai Express. Loved their beef teriyaki bowl with rice. Very filling, and cheap. great place for a quick bite downtown. Last trip, they'd renovated to make it less like a snack bar and more like a diner. They advertise the $2.99 shrimp cocktail, but it's not that much. The one I got was a scoop of tiny shrimp. It's worth the $3, but don't expect gourmet quality or quantity.
https://fremont.boydgaming.com/dine/lanai-expressLots of other places I've been, but many no longer exist or are not the same.