Some people may think that giving it a 10/10 is a bit of a stretch but it's really not. The best kdrama i have ever seen and Easily one of the best shows I've ever seen. Everything was a straight 10 for me.

Firstly, the cast. I actually had never seen any of these actors before which was surprising since I usually watch Kdrama's where there's an actor I admire or like and that leads me to more actors and more dramas. For Vincenzo, I purely watched for the plot since I wanted a new drama to watch. The cast of Vincenzo was perfect by far.
Song Joonki was amazing as Vincenzo. He has that lasting look in his eyes that make him look like a strong character that's been through a lot. he portrayed Vincenzo so well and I was really impressed. He gave me mafia vibes.
Ok Taecyeon was incredible. Watching him in Vincenzo made me binge watch all his other dramas and he is one of my fave actors now. He was actually terrifying in Vincenzo, he played his character flawlessly and expressed a psycopath really well. His eye's were on point and caught the craziness of his character. Jang Han Seok is a scary and over dramatic villan so I think it would mess up his character if he wasnt played very well but Taecyeon played him perfectly. He managed to make the villan funny in a crazy and over-the-top comical way and made it natural at the same time. Not to mention the way he switched personalities so quickly. so intense. very impressive
Jeon Yeobin was really funny and made a perfect Chayoung. she was quite sassy and stubborn, at the same time she was determined and straightforward. I loved her character and didnt find her annoying at all. She seems like a really funny person behind the scenes as well. Vincenzo and Chayoung were a perfect couple
Kwak Dongyeon played a very versatile character and was also really impressive. Definitely the perfect Han Seo, after he befriended Vincenzo there was a change in his entire vibe and it was clear that he was beginning to step up. he acted that out so well and so many people ended up loving his character. He had great stage chemistry with Taec and they worked together so well. I would love to see him have more lead roles
The supporting roles such as Choi Myunghee and Han Seunghyuk were also played flawlessly. Myunghee and Han Seok make an amazing team. Myunghee is an evil genius and Han Seunghyuk was great for some comic relief. he was a funny character played really well. I also enjoyed Seo Miri and Mr. Nam's roles very much.

Then the plot. The plot was so well thought out from beginning to end. the cinematography of the show and effects were also great. I love how the show perfectly portrayed the fact that there are no hero's and villans. everyone is good and bad. the mafia quotes from Vincenzo were really inspiring. I love the theme of revenge too. The way Vincenzo got revenge on everyone was genius. The antagonists died in such a ironic and satisfying yet brutal way. The whole story was so thrilling, especially the courtroom scenes.
Something about Vincenzo that made it so enjoyable to me was that... It doesn't make a whole lot of sense. As people have pointed out, this drama has quite a lot of plot holes and ridiculous moments but that's one of the reasons I love it. It's so dramatic, crazy and entertaining. I can just sit there and chill while watching it instead of having to loose braincells trying to figure out mastermind plot dramas (*cough* Mouse *cough*). It let's me just chill and have fun watching, it's not some crazy genius murder mystery, it's pure drama gold. It's also very emotional at some scenes.

I generally love the idea of Babel, a corrupt company. I love that Jang Joonwoo acted like such a foolish and cute intern then turned out to be the real villan. Watching Vincenzo and Chayoung try to defeat Babel was very fun and interesting.
The music and OST (original soundtrack) were perfect. This drama really blew up when it came to the music and it has some of my fave OST's ever especially "Adrenaline" and the classic violin music that was showcased at the first scene. The music was outstanding and really created the atmosphere and vibe of the show.
the sets were really grand and beautiful and the mafia aspects were done really well. The grandness of the sets really set up the show beautifully.
another part of Vincenzo that I really love is the Jang Brother's. I loved their relationship. even though Han Seok abuses his brother, he still seems to care about him a tiny bit in his own twisted way. At least thats how I see it, I think they're relationship is really interesting Dongyeon and Taec nailed their roles. I would've loved to see more of them
Everything about this drama is phenomenal and Its completely worth watching. It had a great amount of everything and was perfect in every aspect. Vincenzo and Chayoung made an amazing couple. The scenes in the courthouse were so fun to watch. some bits are very lighthearted, there's a lot of comedy, there's a lot of action.
we all have different taste and this drama was totally for me! it is a GEM and I could talk for hours about why I love it so much. I love how Han Seok is a true villan, he's not just some sad villan who had a bad life. His childhood probably was kind of messed up but he is still remorseless. I even love the slapstick comedy and I found it hilarious. Perfectly written and executed, not to mention the amount of incredible actors I discovered from this show. I kinda dont want a part 2, The show is perfect like this. There was some romance but not a lot so it didnt take over the story.
The female lead also didnt try to change the male lead into a good person. she supported Vincenzo for who he was and teamed up with him. she fell in love with him for who he is, she didnt try to make him a better person. She accepted him even though he killed and tortured people. I think they had a very good relationship. Vincenzo was also very respectful to her and they seem like a genuine couple.
It's also very unique and cool to see that Vincenzo is still the same man at the end of the show, his love for Chayoung didn't change who he was. He's still an anti hero and proud of it!
Also, I frankly dont care that Vincenzo and Chayoung could only see eachother once a year. Vincenzo is a murderer and a torturer and in my perspective, he is a horrible person . Im glad he and Chayoung were seperated, he deserved some sort of punishment for acting as if he gets to judge people. It was satisfying to see the villans die in such poetic ways.
Perfect drama! 10/10. I enjoyed every moment of it and frankly, I feel so blessed that this drama exists. I could watch it over and over. I could even say it's a cinematographic masterpiece, no exaggeration. I can definitely understand why it wouldnt be everyone's favirout, but personally, I have no complains about this work of ART whatsoever.