I'll say Midway, but recently made my first order from Natchez and next time I need powder/primers and they have a free hazmat offer if spend $100, I'll definitely order from them.
Midway is great because they just have everything. Brass, bullets, accessories, you name it, they got it.
For reloading presses, reloading equipment, and other accessories, I try to hit up Walmart's website because they usually have some stuff, just depends if it's the stuff you want. When they do, it's usually the same as Midway, but with free shipping and easy returns.
I buy my scopes through Walmart's website exclusively now.
If I'm buying factory ammo I'll usually buy it from either Sportsmansguide or Cabelas. Cabelas prices have been higher lately, usually 2-4 dollars more for ammo than SG, so I've been getting more from SG lately. It shows too as I looked at my order history for Cabelas and over a year passed from my most recent order to my last one.
Prices for other stuff at Cabelas is starting to get ridiculous; Cabelas is slowly becoming the new Gander Mountain. $50 for a 33 round Glock magazine when Midway has them for $35? Unacceptable.
CTD can go straight to Hell while Opticsplanet can tailgate them on the way.