exeternal hard drives for Windows 2008r2

For what purpose?
You have USB and a few other attachment standards out there ,so good is relative.

All USB3.0 or 2.0 connected drives must work with Windows Server 2008R2. A question is - what are you going to use these drives for? As backup storage? Should they be compact or the size is not the issue?
Compact USB drives are small 2.5Inch drives which one can put into the pocket. Desktop drives though external are bigger, like this: http://www.wdc.com/en/products/products.aspx?id=870

The most giant drive makers are Seagate and WD. They are doing the drives of almost similar quality and their drives must work on your server. If some of them do not work then I would suggest checking out why, is it the lack of power on USB port or the drive is defect itself etc. Each case should be considered separately. Because there are no  good and bad drives by default. They are all good drives.

If you need to use them together with built-in Windows backup, then you will have to get 512 sector disks. New 4k sector disks won't work with the built-in backup tool.

Get a USB dock similar to the one below:

http://www.newegg.com/Product/Product.aspx?Item=9SIA6PF3H24346&cm_re=usb_disk_dock-_-9SIA6PF3H24346-_-Product

Then get older used HD's you can drop into that dock. If they are around 5 Years old they will be 512 sector disks. Newer disks will mostly be 4k sector disks and won't work with windows backup.

Another option you have is to use a 3rd party backup utility rather than the Windows Built-in one. 3rd Party tools can also backup to 4k sector disks, and then you can also use newer disks with the dock above.

You might find BackBlaze's articles on drive reliability useful... there is quite a lot of data available.

https://www.backblaze.com/hard-drive.html

Based on their experience with 40,000 hard drives.  HGST the best.

The only issue is that the referenced article seems to be based around consumer disks and does not talk about Enterprise disks

Any disk, whether consumer or enterprise, will work fine with any server OS when connected via USB. For that you don't need anything expensive and certainly not an enterprise class disk. Enterprise class disks are only needed internally together with hardware RAID controllers.

The only real issue with external disks and server 2008/2008r2 OS's is when you try to use 4k disks with Windows server backup, as that utility requires 512 sector disks and just won't work with 4k disks. If you don't use windows server backup, then there is no problem with 4k disks either and anything should work.

In addition to BackBlaze, several other articles say that the primary difference between 'consumer' and 'enterprise' grade disks is not the failure rate but rather the length of the warranty.

Actually most of the WD NAS to Enterprise disks are shipping 512byte  native ,plus their ECC is better than desktop models.

A double parity error is not a thing of beauty when it comes to data reliability.

I connected the drive to a desktop and it needed to be formatted.  Once I did this it also worked on the server.

Strangely your question and the answer are not suiting to each other at all.