ZIF socket, 28 pins

Each time You need program more than few microcontrollers (like ATmega168 czy ATmega328) You will find that placing them in sockets/breadboard is time consuming.

First You need straighten pins, next even if You straighten pins still You need to be careful yet to use some force when inserting and removing chip from socket.

In that case socket ZIP (Zero Insertion Force) will save You time. Place chip, lock it in with a lever and ready. Removing is also very simple.