- always check the MD5 before burning the ISO. If you keep getting the wrong MD5 from one of our mirrors, please tell us on the forums.
You should try out metalinks at least for your ISO downloads. It's a simple XML file that can list your mirrors and the file's checksum (which is automatically verified once the download is done) and repair information to fix the file if theres an error during download. OpenOffice.org, openSUSE, Arch, and other distributions use it. Downloads are REALLY fast because it can use multiple mirrors at once.
aria2 is a command line client that works really well. but there are other clients on all platforms.
If anyone's interested, I'll make one up for the latest ISO.