It depends on what you need to display and with what level of graphics. An 8-bit microcontoller is sufficient to display some basic graphics. Check this **broken link removed**
It is up to waht you need.. with an FPGA you can make it for sure with a full resolution.. but it might be overkill if you use the FPGA just for the VGA controller.... It is possible that a simple microcontroller can make the job.. but you probably going to have some reduced resolution with a simple 8 bit micro. DSP would be suitable if you need some video processing.. but you probably can manage that on a FPGA too.