The 4D Systems displays are pretty nice, but their OLEDs only come in sub-2" sizes. If that's all you need, they're not a bad option. They use a simple serial interface and have a fairly well-documented API. They also have SD slots built-in, which can be used both as image/video storage for the display and as storage accessible by your microcontroller.
I've been writing a library that currently has something like 95% API support for their OLEDs' serial interface. If you decide to check them out, you can find my library on github at http://github.com/planetarian/4Duino
There are some other libraries out there for the displays as well, though to my knowledge there are only two (including mine) that are being currently maintained. The other one has a thread on these forums somewhere too.