I guess it depends what the person is into. If they are familiar with emo then I would start with clarity. It might scare the average listener away imo since it's so raw.
I would never recommend Clarity or Bleed first, to be honest. The former is long, ambitious, and kind of unwieldy. I agree with those who said it's inaccessible. As for Bleed, I don't think it's a great encapsulation of their strengths. I guess I see the logic in recommending their most commercially successful, but as I find that album to be the clear weak link of the 1999 - 2013 streak, I wouldn't start there. Futures is by far the best starting point, imo. It has the introspection of Clarity, the accessibility of Bleed, and the glossy production of Chase. It also has a good handful of their best songs.
Tough question! I always tend to start with the fan favorite if I am getting into bands but for JEW I'd suggest. I would put clarity higher but depends if you're into that kind of slower, emo music. Futures is my favorite from them then Clarity. Futures & the Stay on my side EP BA CTL Clarity Invented Damage
the further down, the sadder it is Damage Invented Bleed American Futures Chase This Light Clarity Futures, CTL, ad Clarity all have moments where they could be #1. Futures has the most hopeful lyrics of those 3 though (title track and The World You Love especially)
i wouldn't say it's a sad sounding album big casino - booya let it happen - doesn't sound that sad always be - happy carry you - happy electable - givener happy gotta be somebodys blues - song sucks feeling lucky - happy sounding here it goes - happy sounding chase this light - positive fire fight - sounds sad dizzy - sounds good not sad