This may be worth bookmarking. Airfare watchdog has links to around 200 airline route maps. From Adria Airways to Yemenia 

It is mostly accurate! I tweeted them this week to let them know of a couple of out of date links.

All the big ones are there (eg American Airlines, British Airways,  Delta Air Lines, Emirates, Etihad, Lufthansa, United Airlines) plus some smaller ones (eg Nature Air, Regional Express).

There are  a few missing carriers (Scoot, Air Malindo).

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