Best answer: When it comes to its exclusive games lineup, Sony still remains king, and you're getting a machine known for its solid performance.
PlayStation has a lot to offer that Xbox is lacking, most notably in the exclusive games department. Though Microsoft has shown a commitment to growing its first-party portfolio with the acquisition of new game studios, Sony already has several studios under its belt that have been pumping out quality content for years, whether they be new IPs or established franchises.
Titles like The Last of Us, Uncharted, God of War, Spider-Man, and Horizon: Zero Dawn have all been heralded as some of the best games ever made, and they are all only available on PlayStation. Where Microsoft seems to be pushing for more social experiences, Sony is doubling-down on high-quality single-player experiences that are getting buzz from critics and fans.
Both PlayStation Plus and Xbox Live Gold allow members to snag a few free games each month, but PS Plus usually has the better lineup. Not only do you tend to get newer games offered through PS Plus as opposed to older titles on Xbox Live Gold, the monetary value tends to be greater as well, with PlayStation offering $1,287 worth of free games in 2017 compared to Xbox's $1,029.
PlayStation 4 console sales numbers alone exceed well over 80 million, dwarfing those of Xbox One (although experts do say that Xbox One sales are up). Earnings reports peg PlayStation Network monthly active users at over 80 million as well, while Xbox Live hit just 59 million monthly active users in Microsoft's third fiscal quarter of 2018. Odds are that if you have friends who play video games like you do, they're likely on PlayStation. Though cross-play functionality is slowly being implemented in a handful of games, if you want to play with your friends, you'll likely need a PS4 to do so and with one.
Higher-end model is relatively cheap
The PS4 Pro may not have a power advantage over the Xbox One X, but it does have a price advantage. For only $400, compared to the $500 price tag of an Xbox One X, you're still getting a 4K-capabale machine that can run games at 60FPS, albeit less frequently than the competition.
If you're short on money and don't want to break the bank, the price may be its biggest selling point.
How important is performance?
Certain people live and die by a game's performance, so you'll need to ask yourself how important that aspect is to you. The PS4 already runs better than a standard Xbox One, though the Xbox One X does beat Sony's higher-end PS4 Pro model in terms of raw computing power. Despite this, the PS4 Pro's performance is by no means bad in any way, so you won't be missing out on much.
PlayStation 4 vs PlayStation 4 Pro
Related to the above section, the biggest difference between either PlayStation model is how well it can run games. While the base PlayStation 4 can deliver crisp 1080p visuals, the PS4 Pro can bump resolutions all the way up to 4K, containing four times the amount of pixels. Both consoles are technically capable of running games at 60FPS, but the Pro will hit this mark more frequently. The PS4 Pro is the way to go if you truly care about even the smallest performance advantage and have a 4K television to view its crystal clear graphics. For those with a 1080p display or those who just want to save money, the base PS4 is still an impressive machine.
Any game released for PS4 can also be played on any PS4 model. There are no "Pro exclusive" games or vice versa.
Popular and reliable
PlayStation and Xbox can go toe-to-toe in a lot of regards, but Sony's exclusives catalogue tends to blow Microsoft's out of the water. Not only that, but your PlayStation Plus membership certainly goes to good use with quality free games each month.
That 4K goodness
PlayStation 4 Pro
The best Sony offers
If you want quality exclusives along with the best performance possible on a Sony machine, upgrade to the PS4 Pro.