The M60 SBS Bus ….
From where I live on the Upper East Side of Manhattan, the easiest way to get to LGA is either by taxi (if the flight is very early in the morning) or by the M60 Bus. The M60 Bus begins on the West Side of Manhattan and crosses to the East Side of Manhattan on 125th Street, and continues over the RFK Bridge (fka the Triboro Bridge) into Queens and LGA. Many of you know about the M60 Bus, which is also convenient from other places in Manhattan because you can hop on any of the main subways from 125th Street and head downtown, for $2.75 in all. It is now a Select bus. You can find all of the details on the M60 SBS here. You could even go from the M60 Bus right to MetroNorth Harlem Station on 125th Street if Westchester or Connecticut is your destination.
The Q70 Bus….
Since mid-2014 there has been another alternative, and one that works great. The Q70 Bus is a limited bus that essentially makes only two stops en route to/from the terminals at LGA. It is a faster option from Queens or Manhattan because it avoids street traffic in Manhattan. It is also a great option for travel to or from Long Island since it stops at the Woodside Long Island RailRoad station. The Q70 Bus only makes two non-LGA stops – at Woodside LIRR and at the Jackson Heights- Roosevelt Avenue subway stop (the E, M, F, R and 7 trains all stop there). The Q70 Bus runs frequently to LGA, operates 24 hours daily and takes approximately 10 – 15 minutes (I would allow more time just in case).
Here is a full list of public transportation options available to/from LGA and JFK.