Fiber glass batts are probably the most common type used in the U.S. They are typically R-13 or R-30 if 3.5 or 12 inches thick and can be used for all new walls, including foundation walls.
They are very energy effective. Studies have shown batt insulation can reduce the amount of energy required to heat and cool a home by as much as 50 percent. Along with lower energy bills, your home will be more comfortable year-round.