Yflyer From United States of America, joined Feb 2007, 841 posts, RR: 1 Reply 1, posted (4 years 10 months 3 weeks 10 hours ago) and read 2181 times:
According to the comparison chart on seatguru.com, for domestic economy class it's JetBlue, which ranges from 34"-38" on their A320s. If you want to count United's Economy Plus, it's 36" on the A320 and 757-200.
For international economy, it looks like it's Thai Airways at 36" on the A340-500, also according to the seatguru.com comparison charts, but they don't include every airline.
Coolfish1103 From United States of America, joined Feb 2008, 384 posts, RR: 0 Reply 2, posted (4 years 10 months 3 weeks 9 hours ago) and read 2169 times:
I believe Thai Airways' A340-500 is Premium Economy, not Economy.
For international, I think it's EVA Airway's B747-400 Upper Deck has the most generous pitch of 36", and it is truly 36".