Let's start with the simplest AV receivers and work our way up from there.
Marantz has a pair of really compelling slimline receivers that may be perfect for your needs, assuming what you need is straightforward simplicity and a chassis that's a little less obtrusive than most.
If you just want five ear-level speakers, the NR1509 is a 5.1-channel offering that takes up half the space of a normal AV receiver, making it a great option if big black boxes aren't your thing. The NR1609 ups the channel count to 7.1, which may be enticing if your room is a little deeper and there's plenty of space between your seat and the back wall.
Since you're getting so many features in such a slim package, there are potential downsides. Neither of these relies on Marantz's HDAM circuitry (so ignore what I said above about the general sonic differences between Denon and Marantz), and output is limited to 50 watts per channel. The NR1509 also only has five back-panel HDMI inputs (and two around front), so if you have a lot of HDMI sources, the NR1609 may be a better pick (it has seven HDMI inputs on the back and one up front). The NR1609 will also scale video from your source devices up to 4K, whereas the NR1509 offers no video scaling. That's an important consideration, even if you don't need the two extra channels of amplification. In short, between the two I think the NR1609 is the better pick for most people, even if your speaker system is limited to 5.1.
If, on the other hand, you don't mind installing a full-sized receiver, and you're looking for something cheap and reliable, I really like the Denon AVR-S740H. Yes, this 7.1-channel receiver supports Dolby Atmos and DTS:X (in a 5.1.2-channel configuration--which, if you'll remember, means 5.1 plus two overhead speakers), but that doesn't mean you have to configure it as such. You can use it as a 7.1 or simple 5.1 receiver with no problems. Its 75 watts of power per channel means that it's a better choice than either of the slimline Marantz offerings if you have a mid-sized room or less sensitive speakers.
You can also use the Audyssey MultEQ Editor App (an extra $19.99 purchase) to tweak the settings of its room correction to deliver great results in your room. With a total of six HDMI inputs (five 'round back, one up front), the AVR-S740H is a little limited in terms of connectivity, but if that's enough for you, have at it. Perhaps more importantly, though, it doesn't feature video upscaling, so if you watch a lot of 720p TV channels on a 75-inch 4K TV, you might instead step up to something like Denon's $550 AVR-X2500H, even if you don't need as many HDMI ports as it provides.
The next significant step up is Denon's AVR-X3500H. This 7.2- (not 7.1-) channel receiver is where you start to get into independent measuring and setup of more than one subwoofer, which usually (although not always) results in smoother, more even bass response from seat to seat in your listening room. If you want to go Atmos and DTS:X, the AVR-X3500H is good for a 5.2.2 setup. And if for some reason you find that its 105 watts per channel of amplification isn't enough for you (if, say, you move it to a bigger room), the AVR-X3500H has 7.2-channel preamp outputs, meaning you can add your own external seven-channel amp to the equation and just use the receiver as a preamplifier. Originally priced at $999, this one seems to have recently benefited from a price drop to $749, making it a compelling mid-level offering. A total of eight HDMI inputs (seven around back, one up front) mean that most people will have a little bit of headroom in terms of digital AV connectivity.
For the semi-equivalent Marantz offering, I really like the SR5013. Unlike the aforementioned NR1509 and NR1609, this one does feature Marantz's own proprietary amp circuitry, so you'll likely find that its sound is dynamic and more musical to your ears than that of the Denon AVR-X3500H. Otherwise, their feature sets are pretty comparable: both offer AirPlay 2 and HEOS multiroom streaming, along with support for all of the current AV standards. The biggest difference between them, aside from their amps, is that Denon offers a second-zone HDMI output, and the Marantz has a multi-channel analog input (which may be important if you have an audiophile Blu-ray or UHD Blu-ray player with DVD-Audio and/or SACD playback capabilities).
Most object-based surround sound enthusiasts consider four overhead speakers crucial for getting the most out of these formats. That's likely why most HomeTheaterReview.com readers opt for something along the lines of Denon's AVR-X4500H when buying a new receiver. (The previous year's equivalent model, the AVR-X4400H, was 2018's best-selling receiver via our Amazon Affiliate links--by a huge margin--and it's still a great option if you don't mind giving up a few new features.)
The AVR-X4500H is a 9.2-model model that can be configured as 5.2.4 (or 7.2.2) relying on its internal amps alone. And if you want to add your own external stereo amp to the mix, you can use its preamp outputs to expand it to 7.2.4 easily. (The specs on Denon's website disagree, but I've tested it. Those published specs are just wrong.) Its 125-watts-per-channel output is plenty sufficient for most mid-sized rooms and most speakers, unless you just won't settle for anything less than IMAX levels of sound output. Speaking of which, it also supports the new IMAX Enhanced format.
Marantz offers its semi-equivalent SR6013 for about the same price. It doesn't boast as much power per channel as the AVR-X4500H, but it does rely on Marantz's proprietary HDAM circuitry amplification circuitry, so if you listen to a lot of music in your media room or home theater, you may prefer its sound. It also boasts 7.1-channel analog audio inputs, something the Denon lacks.
In terms of power ratings, the Marantz SR7013 (also a 9.2-channel receiver) is a closer competitor, although it sells for a good bit more (likely due to its HDAM amp circuitry).
All three of the receivers recommended at this level offer a total of eight HDMI inputs (seven on the back, one up front), so you're almost certainly good in that respect.
It's highly unlikely that someone looking for this sort of shopping advice would need or want anything more than the products mentioned above. But on the off-chance that you have a good reason to expand beyond four overhead speakers (maybe you have a couple of rows of seating in your media room, for example), Denon's AVR-X8500H 13.2-Channel AV Receiver is a beast of a machine. For Dolby Atmos, it can be configured for 7.2.6- or 9.2.4-channel listening, although with DTS:X material its limited to decoding of 7.1.4 or 5.1.6 channels. And with 150 watts per channel of output, it's plenty powerful enough for most rooms and most speaker systems, and it's also eligible for upgrades down the road should its features and connectivity become outdated. You can read our review of the AVR-X8500H for a complete rundown of its features and capabilities.
I really love Anthem's current lineup of AV Receivers. Just to reiterate the deciding factors mentioned above: they have more robust amplification than most mass-market receivers, and their Anthem Room Correction system is absolutely aces. Could you get better results with an AV receiver equipped with Dirac room correction? Maybe. If you really understand room acoustics and know what you're doing. And if some manufacturer would only offer Dirac in an AV receiver without crippling its customization capabilities (TL;DR: for some reason, unlike the Dirac-equipped preamps I've reviewed so far, AVRs with Dirac limit your ability to tweak channel settings once you've measured and uploaded your room correction results. Why? I have no idea. If you want Dirac done right, get an AV preamp.)
Then again, audiophile receivers rarely follow the same yearly update cycle as mass-market receivers do, so they can get a little behind in terms of features pretty quickly. Thankfully, Anthem's current lineup isn't behind at all in terms of video connectivity, and the only major feature they lack that may be important to you is 7.1-channel analog inputs.
So, which one is right for you?
In short: the MRX 520 if you just want a 5.1- or 5.2-channel sound system and have a relatively small room.
The MRX 720 is a better choice if your room is a little bigger or you might want to up the channel count to 7.2. The MRX 720 also features 11.2-channel preamp outputs if you want to go full-blown Atmos/DTS:X and don't mind bringing your own amps to the party.
If you want an all-in-one audiophile Dolby Atmos/DTS:X solution without adding amps, the MRX 1120 is where it's at. If you'd like to audition any of these Anthem receivers to hear if the difference is worth it for you, you can find your nearest dealership by following this link.
Wait, I have a few more questions...
Lots of stuff. Like Auro3D (another 3D surround sound format with limited distribution). And oodles of considerations in terms of multi-zone AV distribution. And advanced control systems. And wireless music streaming. And so on.
I also left a lot unsaid in terms of HDR10, Dolby Vision, and HDCP 2.2 copy protection support, because all of this year's offerings are pretty much on the same ground when it comes to all of that.
Mainly to keep this article from being 50,000 words long. But also, because this isn't a guide for home theater enthusiasts, as I mentioned from the giddy-up. I'm focusing on the features and functionality that are most crucial to most normies.
Because, again, if you already have an AV receiver that you love the most, this guide isn't for you.
Exactly zero dollars. Although the former PR guy for Denon and Marantz did take me out to dinner last year when I was in San Diego, and it was pretty delicious. But he's not with the company anymore.
I like it. It's Zora Arkus-Duntov's lifelong dream finally realized, and I think it'll make the C8.R more competitive against the Ford GT on the track.
I've honestly forgotten at this point.
• Read Room Correction Revisited at HomeTheaterReview.com.
• Read How to Pick the Right Amp for Your Speakers (or Vice Versa) at HomeTheaterReview.com.
• If you want more in-depth coverage of individual products, visit our AV Receiver category page.