The best way to store a large data into SDRAM

USB is pretty easy to do this with, a long time ago I made a dumb little USB interface to bridge an FTDI chip to SOPC Builder in a schematic. They give you drivers for free and so all you would need is a DMA and maybe a protocol if you want to build more intelligence into it. I don't know what I did with it since I just through it together in a hurry but it only took a few hours to get my PC sending data back and forth at around 10kB/s (Nios II was moving data one by one so a DMA would be way better in terms of performance).