Which protocol (FTP or HTTP) is better for download/upload small or large files?

I was looking at different websites where download options are available, and always find different way to download same file. Over FTP or HTTP. I was wondering which one is better and should preferred over the other one? And why?

The question should not be a server question, but rather a client question. Are the clients to be web browsers? If so, HTTP. If they're advanced &| you want to have a system-user-based control over several files, then FTP. FTP has some side benefits, but only if your user/consumer/client can take advantage.