I love Legoes because there's so much you can make and do with them. It's no surprise that I adore The Lego Movie (and its sequel) and The Lego Batman Movie. Lego City Adventures shows a lot of potential and is the best LEGO TV show to date.
The premise is very intriguing. Although the stories are mostly self-contained, the show revolves around the citizens of Lego City trying to stop a master criminal, meaning there's an overarching plot (somewhat). I like that the arc is subtle, similar to TOTS and Amphibia.
Another thing I like about the show is the fact that it focuses on a bunch of characters rather than just one. It's a very good thing, as it allows the show's rich and diverse cast of characters to have a chance to shine. There's the overly heroic cop Sgt. Duke DeTain, crisis-ready fire Chief Freya McCloud, grumpy street sweeper Shirley Keeper, among others. They all have unique and deep personalities. The focus on many kinds of everyday heroes also gives me Higglytown Heroes and Rescue Heroes vibes.
The dialogue is very clever, there are several good morals like "Sometimes, you can't always stay exactly on schedule", and the animation and FX are well done. If you like Legoes, Rescue Heroes, and/or Higglytown Heroes, this show is for you. Definitely the most underrated Nickelodeon show right now!