I don't recommend the show for everyone, but it does excellent fan service for anyone who likes Star Wars. Some of the starship battles go beyond the scope of the movies. Meanwhile, a few of the lightsaber duels are beautifully choreographed and certainly true to the heart of Star Wars. Some of the character arcs are sensational. It especially makes Anakin's turn to the Dark Side more convincing as we see him struggling with the burden of being the Chosen One and have good reason to start distrusting the Jedi Council. I also loved how the stories made me care about the clone troopers--who are all searching for identity in a universe where millions of others look and are raised exactly alike. This also makes the betrayal of Order 66 much more emotionally charged.
It also introduces new characters, and some of my favorite characters in the Star Wars universe. The one to really watch is Ahsoka Tano, Anakin's apprentice. By the end of season 7 ... well, I'll leave that for the spoiler section below. I also grew to like Asajj Ventress (who bears resemblance to the villainess in my Episode II script) even though I hated her in the early seasons. They did an amazing job fleshing out her character. Lastly, I really liked Fives, Echo, and Rex out of the many clones who were introduced. I'm still amazed that the same voice actor managed to give such nuanced performances so that each clone still felt unique and identifiable. There's also the surprise appearance from one character in Star Wars lore whose story was not only riveting, but really pulled all of the threads of the larger story together.
If there's one thing that I struggled with, it was knowing how the larger story turns out in the end. The writers still managed to throw in some amazing twists and surprised, but the entire time I'm watching, I knew that this story did not end well for this generation. These were the events that lead to the rise of the Empire, and this show does a superb job of showing how Palpatine had carefully manipulated all sides to bring about his ultimate plan.
Another issue is that this took a long time to watch. There's about 44 hours worth of content and some of it (the political episodes with Padme in particular) really seemed to drag. Others, like R2's adventures with "D-Squad" were really hard to swallow between some of the more serious stories around it. And others still, like the ones with the strange god-like family that represented the Force, were just ... weird. If you would like my advice on what is worth watching, and what is worth skipping, continue on. BTW-the original Clone Wars movie is completely worth skipping. The only thing it does worthwhile storywise is set up Ahsoka as Anakin's apprentice (and provide the reason for the nickname "Snips" that he gives her). Also, I watched them not in broadcast order, but in the chronological order that Disney has posted--if I hadn't, I think that some of the episodes would have confused me as they are not all in order for the first three seasons (and a few in seasons 4, 5, and 7 [the middle arc in 7 should be before the first arc]).
What follows includes spoilers for both The Clone Wars and Mandalorian. If you have not seen other and want to watch them fresh, don't continue. If you watched Mandalorian and didn't plan to watch The Clone Wars, I recommend continuing as it looks like season two of Mandalorian will have some significant tie-ins to The Clone Wars (both had the same producers, so that's not much of a surprise).
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Okay, I largely decided that I needed to watch The Clone Wars when looking up the significance of the strange lightsaber (the Darksaber) that showed up at the end of season one of the Mandalorian. I discovered that the weapon (which originated in the non-canon Extended Universe) made its first canon appearance in The Clone Wars as part of the story arc dealing with an organization called Death Watch on the planet of Mandalore (you might already be able to see the connection). I later learned that Ahsoka, Rex, and Bo-Katan (played by Katee Sackhoff herself) will also show up in some form during season 2. As I watched the series, and grew to love the characters, I became even more excited.
Thus, if you wanted to skip episodes, but still have a background before going into season 2 of Mandalorian, I would recommend watching the following: Season 1: episodes 2-5, 9; Season 2: episodes 1-3, 5-14; Season 3: episodes 1-2, 5-6, 12-14, 18-22; Season 4: episodes 7-14, 19-22, Season 5: episodes 1-9, 14-20; Season 6: episodes 1-4, 10-113; and Season 7: 1-4, 9-12. These episodes focus on Ahsoka's development, the introduction and change of Asajj, the arc of Darth Maul--which is tied to the Darksaber, the development of Fives and Rex, and the background behind Mandalore and its culture.
I still need to see Rebels--which I will start next week after watching Revenge of the Sith (now that I know the characters in the background). I know that some of the storylines from the Clone Wars get wrapped up in Rebels (especially with Rex, Ahsoka, and Maul). I also know that the Darksaber continues its story after it disappearance in the Clone Wars. I should have it all watched before Mandalorian returns in October.