Here is the list of Airlines offering Inflight WiFi and links for more information ( wi-fi Internet service on an airplane). These airlines has has different plans like subscription plans, pay as you go and pre-paid plan ( buy before you fly). Click on the respective airline link below to see the plan and cost details
Delta Air Lines – In-flight WiFi Access
Southwest Airlines – In-flight WiFi Access
United Airlines – In-flight WiFi Access
American Airlines – In-flight WiFi Access
Alaska Airlines – In-flight WiFi Access
Lufthansa FlyNet – Internet on board
Emirates – Wi-Fi in the Sky
Singapore Airlines – Inflight connectivity