Nebody own and external hard drive? whats the most reliable brand at a reasonable price?

admittedly, i dont know a whole lot about computers. i wanted to find out from people who owned them, what the most reliable external hard drives are and whats the largest capacity drive you can buy? these are good if your friend has a bunch of video files on his comp that you want to copy right? you can just drop off your drive and he can copy real easy with a USB...i want to copy of bunch of anime from my friend ...