I first saw this anime a couple of years ago and absolutely adored it - here are both my previous and current thoughts about it
Story 9/10
The story is both straightforward and complex - when humans die they are sent to "purgatory" where their lives are judged by arbiters who determine if they will be reincarnated or be sent to the void (they say heaven or hell because it's an easier concept for the dead characters to grasp, but they mention later that its actually reincarnation/the void). While stories about life after death are pretty common, this one took an interesting spin on it - arbiters have their own bars in purgatory where the dead are sent to be judged. In simple terms, when you die you go to a bar XD I thought this was pretty unique (plus the art aesthetic of it is gorgeous, but I'll come back to that). Arbiters judge the dead by removing their memories of being dead and having them play games like darts, bowling, billiards, twister, air hockey, etc., and judging their actions based on what happens after their memories come back, doing so from a completely unbiased, logical, and detached standpoint (Idk if I'm explaining it very well, it's all explained in the first 2 episodes anyway so go watch them). At first, I was skeptical about the way the arbiters judged the dead and didn't know if it was very ethical, but it's actually brought up later in the story and furthers a dilemma of whether or not people need to empathize with others to properly judge their actions or if it should be completely logical. Plus, the ending will have you in tears. Trust me. Just know, however, most of the subject matter in the episodes is very sad and may disturb some people if they've dealt with anything similar (i.e., abuse, depression, misunderstandings, guilt, suicide, etc.)
Art 10/10
Death Parade has a unique and gorgeous art style and a remarkable aesthetic to it. Every scene is full of tiny details to look at, whether it's the liquor bottles on the wall of the bar or the massive chandelier in Quindecim, or the unique game setups, the wallpaper in a bedroom, a stained glass window, or the purplish overtone to it all (as an artist I appreciate these things unconsciously as I'm watching it XD). Though the character designs are fairly simple, they're by no means boring or lazy. The show focuses more on the mental issues of the dead characters and internal struggles of the arbiters, so it focuses its artistic talent more on the backgrounds and aesthetics. Both are gorgeous to look at and make you want to visit the Quindecim even if it means death XD
Sound 8/10
The soundtrack for this anime is beautiful and I listen to it myself sometimes. Minus the infamous upbeat intro song, the music is usually very melancholic, intense, or straight-up depressing, and I love it. To me, the music makes you feel like you're far, far away from the real world with no chance of a return, so your only option is to just have a drink and reflect on your decisions and wait for whatever's next. There's one song in particular called memento mori which makes me cry whenever I watch the anime along with it since the scene it plays in is one of the most depressing in the show. For the most part, the music has a bit of a 70s jazz vibe plus some piano music - you know, the kind of stuff that would be played in a bar.
Character 10/10
This show's strong suit is the characters and their developments. From the very first episode, you're immediately interested in these characters and why they are acting the ways that they do. You feel their changes from when they have no memories and are completely innocent to them remembering that they're dead and the pain and fear that they go through when realizing it and lashing out begging to be brought back to life to undo their mistakes. The most incredible thing I think this show accomplishes is that even though you only see most of these characters for 1 or 2 episodes each before they're reincarnated or sent to the void, you still care about them and are interested in their stories. They are all so realistic in their struggles and when they're hurt, you feel them, no matter how likable or unlikeable they may be. Death Parade takes things that we may sometimes take for granted like greed, murder, depression, revenge, suicide, or even just accidents and shows what they do to people on a personal level. They don't just tell you what the characters feel, they let you experience it and see it. Plus, it's not just the dead characters that are amazing, the ones you see throughout the show like Decim and Chiyuki are incredible too. Decim in particular, while not having the most relatable position for most people, is so interesting to watch. His arc, while I won't spoil it, is emotional to watch and will have you in tears by the last episode.
Enjoyment 10/10
I thoroughly enjoy watching this show and have watched it at least 5 times through XD it's one of those shows you can rewatch over and over again only to learn new things every time. Any time I want to rewatch something, it's Death Parade. Even though the character's stories are fairly simple, they are so rich with drama and personality that it feels like a huge present wrapped in a small package. The creators nailed everything about it. Plus, there's a scene when one of the main characters has an extensive flashback scene about her life and the first time I saw it I was bawling.
Overall 11/10
A masterpiece that's in my top 5 anime of all time. The story is unique, the art is very pleasing to the eye and engulfs you in the story, the music is also very enchanting and helps set the mood of the show, the characters are some of the best side characters I've ever seen in any form of media, the show will make you laugh, cry, question human nature, both relax and engage you at the same time, and please any aesthetic needs you have (how many times have I said 'aesthetic' in this lol). As far as I know, it is underrated in the world of anime I think because it's short and doesn't have a massive following, but it has a fandom that loves and appreciates it. I know for sure this will stay in my top 10 if not top 5 forever.