If it's gotta be Y make it LAN Chile or American. The former has a Y product equivalent in many respects to J on the others [make sure you try some pisco sour; better than sleeping pills for knocking you out on LH] or American if you've got any kind of FF status [good for UGs], as well as legroom and Y laptop power [if you want to punish yourself inflight] - NB on the last point, not all Y seats have it, make sure you check at time of seat allocation.