You get better deals for buying in bulk (500+ rounds), marginally worse deals for buying in smaller quantities.

In Utah, I find that Al's Sporting Goods tends to have good prices on ammo. Get Some and Gunnies are hit or miss (good sales, mediocre day-to-day prices), Cabela's and Sportsmans and farm supply stores tend to are pretty stable (never great deals, but always "fair" prices for brick and mortar retail); Ready Gunner is pretty consistently terrible.

For the best deals, try ammoseek.com; filter by "new" (I don't trust remanufactured rounds) and a shipping rating of ">8". This will leave you with some great options (and you can filter those results even more by grain weight or manufacturer).

I've had good luck with some of the following bargain brands: MagTech, Sellier & Bellot, Blazer, PMC Bronze, Browning. Federal aluminum and syntech is also good to go. Oddly enough, Winchester has been a problem brand for me, even though it's owned by the same company that owns Browning and is often priced above the "bargain" brands. From what I understand, Winchester is so big that their quality really depends on caliber and the manufacturing plant (for example, their Lake City 5.56 is great). But when bargain-hunting, Winchester is one of my last choices.

Premium brands (never had issues with) include: Federal, Remington, Speer, Hornady and many, many others.