Your design depends of how many diodes you wanna have.If you make 2x2x2 led cube you have 12pins and this is easy to achieve only with AVR microcontroller.
Hi
I dont know what you really want to realised but if you want to make some effects with more than 2 diodes better use some pic controller. If you want to just turn off and on this diodes u can make it with only 2transistors.