This was a special request/thank you.
I have my very own version of Garrus at work who cheers me up when I feel blue. He calls me Shepard all the time and gives me Turian hugs. He also also scraps with me all the time too (thanks to him I have a nice 2 inch scar on my wrist), but I love him anyways.
Anyway, he wanted Garrus doing Gangnam.