The CFAG12864U3-NFH (just the display) and the CFAG12864U3-NFH-E1-1 (display with adapter board) are great monochrome LCD displays. They are transflective, so they're readable in just about any lighting condition, only needing supplied light if used in a dark environment. For a display with a built in backlight, check out the family of 128x64 Backlit Low Power LCDs.
Integrated Sitronix ST7565P controller
Low power consumption
Ideal for handheld and/or battery operated devices