Lupin the III Part V
Man Lupin the III has become among my favourites, but besides seeing the movie Lupin the First tomorrow I'll probably take a break after that because I'm actually now worried about burning out trying to crank out through the rest of the franchise (with Part II having 155 episodes alone, like holy shit). So with Part IV and V done I'll probably return at a future point and in the long run take on other parts of the franchise in smaller pieces overtime.
After all, gotta make room in my schedule for other things too like Re:Zero season 2.
But I think it's safe to say Part IV and V and possibly Lupin the First are solidified as the "backbone" of my Lupin the III experience.