I wanted to give that a try some time ago and found this which tells you how to transform it into a workstation so more things will work. I for one wouldn't recommend it though.
Also, check to see if your university is part of the MSDN-AA because if it is you can get Windows 7 free (as well as other software and OSs from MS)

Since it's a server OS some gaming functionality is missing by default and will need to be manually installed (and I'm not just talking about running the DirectX installer), and even then not everything will work, especially certain legacy games. For non-gaming purposes it should be mostly identical to Windows 7, however.
Also note that most or all consumer security software will refuse to install on a server environment because they see the server OS and think you're trying to pull a fast one by using a free/cheap personal AV for corporate use.
2008 R2 is also totally unsupported by all games and almost all programs (if they run it is not intentional), so when you run into problems--and you will--you won't get much help from tech support beyond "buy Windows 7 k thx".
Windows 7 is expensive, but it's clearly preferable to trying to shoehorn gaming usage into a server OS. Everything just works right out of the box with 7, and if it doesn't you can get full tech support from software vendors.

I can use Dreamspark, but sadly, my university does not have MSDNAA account. :(
Anyway, thanks for the link, I'll check it out. Oh, and, can you edit the quote a little, as I fixed that last part? :)

The server OS' are good but as has been said you may lack a feature or 2, your biggest issue will be drivers

There's always Linux!

Check my compat list. the server OS's are fine for gaming.
More so since 2008+.
Just install the Desktop Experience role and you are good to go.