STOP - The people replying here saying ANY drive with a SATA or IDE interface will be fine are wrong. Some drives do not support sleep in OS X, research the issue and you'll see it is a known problem. If a drive has sleep issues it does not 'wake' with the machine making the whole power saving option 'Put drives to sleep when possible' non-functional. A drive with this issue will not appear is OS X if the system sleeps the drives after non-usage, it crashes disk utility and system information if you try these after sleep.
Now this thread has already had advice of ANY drive working fine - that's wrong. Someone mentioned Pioneer drives are fine, they are mostly but some have sleep issues in OS X.
Now a lot of drives are plug and play but a little research to avoid those with sleep/wake issues is just good advice, speaking of which the LITE-ON iHES112 does not support sleep on OS X.
Find a drive you like read/write speed etc and then just type the model number and the words 'sleep' 'os x' in google and you'll soon see if it has any issues.
I had no idea of this - thanks for the info.