>>1424Lupin is fantastic and an incredibly accessible due to the vast array of tones it covers. I firmly believe everyone can enjoy something from this franchise. The second series (red jacket) is my favorite, but the first series (green jacket) sets up the backstory for how Lupin and his gang get together so I'd recommend checking that out first.
A lot of people also get into the series through the second movie The Castle of Cagliostro due to Hayao Miyazaki's involvement, so if you're a Ghibli fan that's definitely work a peek at.
Besides the main TV series Lupin produces a TV special every year which are self-contained movies which vary heavily in quality but are mostly solid. A few I'd recommend are Island of Assassins, The Alcatraz Connection, and Voyage to Danger.
I could go on and on, but this franchise is expansive and I like most of it. A Woman Called Fujiko Mine is great for people into darker mysteries, Legend of the Gold of Babylon is a wacky trip for those into cartoonish fun. Poke around a bit and you'll stumble across something you'll enjoy.