straight or 90 deg headers (pins)
I usually use female headers pointing straight up off the board because they accept the most common double-male breadboard wires. The downside is that their mechanical connection to the board is not terribly stable due to the board-end pins being little bitty extensions of the sheet-metal socket inside the header. 

Male headers are much more stable, and a handful of male-female breadboard wires will connect them to a breadboard. The downside of going this route is it invites JRobert's Law of Erroneous Selection: whenever you have more than one kind of similar component, the first one you pick will always be the wrong kind.