What are the connectors used in the arduino mega?
Look for male pin header strip, with 0.1 inch (2.54mm) pitch.

In single and dual row form.

Specifically they are:


8x1 ADCL
8x1 ADCH
8x1 PWML       
8x1 PWMH        
8x1 Communication
6x1 Power
18x2   digital IO (on the side)


Source: Schematics