A list of current display drivers:

AlteraFramereader  - Support for the "Altera Frame Reader IP Core"
ED060SC4           - E-Ink display
framebuffer        - Supports any non-palletized, non-bitpacked color display with a framebuffer
Fb24bpp            - Same as 'framebuffer' driver but supports RGB888 and BGR888 packed framebuffer formats.
HX8347D            - Mid-sized color LCD displays eg RGB565 320x240
ILI9320            - Mid-sized color LCD displays eg RGB565 320x240
ILI9325            - Mid-sized color LCD displays eg RGB565 320x240
ILI9341            - Mid-sized color LCD displays eg RGB565 320x240
ILI9342            - Mid-sized color LCD displays eg RGB565 320x240
ILI93xx            - Mid-sized color LCD displays eg RGB565 320x240 (attempt at a common driver)
ILI9481            - Mid-sized color LCD displays eg RGB565 320x240
LGDP4532           - Mid-sized color LCD displays eg RGB565 320x240
Nokia6610GE8       - Small (130x130) 12bit color LCD
Nokia6610GE12      - Small (130x130) 12bit color LCD (untested)
PCD8544            - Small monochrome LCD
PCF8812            - Small monochrome LCD
R61505U            - Mid-sized color LCD displays eg RGB565 320x240
RA8875             - Mid-sized color LCD displays eg RGB565 320x240
S6D1121            - Mid-sized color LCD displays eg RGB565 320x240
SPFD54124B         - Mid-sized color LCD displays eg RGB565 320x240
SSD1289            - Mid-sized color LCD displays eg RGB565 320x240
SSD1306            - Small monochrome LCD
SSD1331            - Small hardware accelerated OLED display RGB565 96x64
SSD1351            - Mid-sized color LCD displays eg RGB565 320x240
SSD1848            - Small grayscale LCD eg 2-Bit 130x130
SSD1963            - Mid-sized color LCD displays eg RGB565 320x240
SSD2119            - Mid-sized color LCD displays eg RGB565 320x240
ST7565             - Small monochrome LCD
STM32LTDC          - STM32 ART graphics STM32F4 and STM32F7 series CPU's
TestStub           - NULL driver just to test compile
TLS8204            - Small monochrome LCD
UC8173             - E-Ink display driver
UC1601s            - Small (64x132) monochrome LCD
QImage             - Driver that allows rendering into a QImage object (of the Qt framework)
uGFXnet            - Remote Network display (in drivers/multiple/uGFXnet directory)
Win32              - Microsoft Windows (in drivers/multiple/Win32 directory)
X                  - X Windows (Xlib) (in drivers/multiple/X directory)