Subway to LaGuardia

Was discussing Mass Transit w/ +Ben Phenix, and the question came up - Why is there no Mass Transit to LGA? (Mind you, the M60 and Q83 don't count).
The Googles to the rescue...

Dreams of taking the N to LaGuardia

By Benjamin Kabak

The Fiorello H. LaGuardia Airport in Queens is one of the nation’s most infuriating urban airports. It is so close to midtown and Manhattan’s Central Business District that a commuter in a hurry could make the trip in 30 minutes. Yet, it’s so far away because congestion frequently creates trips to Queens that last an hour and 30 minutes. The only public transit option to the airport is a packed and slow bus that, on a good day, goes from 125th St. and Lexington to the airport in a half an hour. (more...)