Simply the best the Dark Souls series has to offer.

The best bosses, Gael, best soundtrack, Gael, best areas, Gael, Midir, Gael, Good story, amazing themes, anything that does the theme "it's okay to let things go" is automatically 5/5 for me.

Though somewhat limited in playstyles due to magic being not so good.

(update):
The story is about what you'd expect from a souls game. Fallen kingdom, lots of lore and names about things you never see, kill four dudes to collect their souls and then bring them to the final boss area to fight the final boss. It does what it says on the tin but with a lot of references and characters from Dark Souls 1 (and some of 2).

It's very rote and I'd almost have a problem with that if it weren't for the meta-narrative and themes presented in the game.

With the degradation and corruption of old characters and locations from the other games, it embodies series fatigue. Its setting, its characters, its bosses, are all tired, exhausted, in pain. They beg for the end, but it always continues (This is literally the plot of the Ashes of Ariandel dlc so it's not exactly subtle). There's always someone to light the First Flame and extend the Age of Fire despite no one wanting it to continue.

The Ringed City dlc takes place where the lore starts, where the first undead are but it also shows the very last things to ever happen in the Dark Souls universe, the very end, and the absolute ruins of everything.

Gwyn couldn't let go of the golden age and we can see the consequences of his actions. And that's what the series, especially Dark Souls 3, is about. It's about letting go and moving on and doing other things in your life. It's about how everything no matter how good or bad, must come to an end and how scary that process is, but most importantly, how hopeful that can be. (You can see this with the painting girl using the literal Dark Soul to paint a new world at the very very end of the game.)

Dark Souls 3 is the last Dark Souls game we'll ever get, and that's okay.