Airline Seat Pitch guide for First class, Business class, Premium Economy and Economy class seats.

[randomness]

http://www.airlinequality.com/Product/seats_global.htm lists carriers worldwide.
http://www.airlinequality.com/Product/seat_intro.htm breaks them out by region.

Those low-cost airlines, like Air Asia (29"), easyJet (29"), and Ryanair (30") really cram 'em in. Most US carriers seem to have at least a 31" seat pitch.

Seat distance isn't everything, of course, but that's what the passenger submitted ratings for airlines and airports are for.