Round IDE Cables / Round Floppy Drive Cables
Round Cables are great if you are tired of dealing with those massive ribbons. Both Round IDE Cables and Round Floppy Drive Cables (yes, they're still widely used) will free up plenty of room in your case and improve cooling by not impeding airflow like a flat ribbon does. Either one of these Round Cables can be especially useful if you have a small form factor case
. Xoxide.com is your one stop shop for all round cables.