AR brand or part selection is a "can of worms" question. Ask a generic question, and you're going to get more information than you can reasonably process. Twenty posts in and you could probably spend several hours or more just researching the recommendations and links there are now. You will get a ton of answers from varying viewpoints because there are a ridiculous amount of assemblers, options, and preferences. People spend hours debating which buttstock or grip to choose from one manufacturer, for instance.
I think the better place to begin is to think about what you like and don't like about what you have now. Sure, reliability and durability are great criteria, however, all AR's of reasonable quality should run at least 5K rounds of without part failure. There are outliers, like those who do "meltdown" videos, etc.
So, the criteria we have are:
Caliber 5.56mm/223Rem
A budget
"Something more reliable than a Ruger 556" - presumably
Buy something instead of build something
Reputable manufacturer with support
Range and HD use
Truly, these are too generic to offer specific recommendations without more preferences. Manufacturers do make run of the mill AR's, but they do specialize in certain things that make them unique.
Here is a list of details that I would think about:
Barrel length - 16" to 24"+. We probably can presume 16" for HD, but we don't know. 14.5" with a P&W FH is annoying if you have to change anything.
Barrel quality - Unlined (probably not), chrome lined, Nitrided, Stainless, CHF, something out there like a Proof carbon fiber, etc.
Bolt carrier group - which manufacturer (or which branding of toolcraft- haha), coating?, C158 vs 9310 bolt material.
Gas system length - carbine, midlength, rifle, intermediate, or some other length someone has concocted and promoted. Midlength is more standard now for 16" barrels.
Carbine or Rifle recoil system - although the carbine buffer tube is almost standard now and simply used with H3 buffer for "rifle length equivalent." But some people do like rifle length stocks.
Furniture - handguard (free float? - how to spend $200 without really trying - haha), stock, grip, VFG?
Trigger - milspec, milspec enhanced/coated; single stage/double stage? There must be great money in AR triggers as there are an incredible amount of choices.
Sling - which one, sling attachments
The point of this list is in part to overwhelm because AR's have a lot of specifics. The Ruger 556 makes most of those choices all bundled up into a generic package for everyday people who trust the Ruger name. While it doesn't take a ton of research since some manufacturers also put together their part builds for the customer, if I were dropping that kind of money on an AR, I would want to have some idea about the specifics of what I was getting. There are some expensive AR's out there that aren't as reliable as some less expensive ones. There are manufacturers who focus on ultimate reliability at the expense of accuracy. With such a diverse marketplace and a huge amount of choices for a large budget, it is difficult to make a specific recommendation.
