Mine was actually a subdued one, because it hit me hard that I was actually moving away from home. When my parents said goodbye after helping me unpack a little, I finished unpacking my clothes and was waiting for the first person to arrive (I was the first one to arrive in my flat).
We all spoke on fb beforehand so we knew roughly who to see. I had my door shut all the while because there was no door stopper. As soon as I heard the first person to arrive, I had to take a deep breath, open my door and take the walk of courage to the kitchen (where my flatmate was with her mum) to meet. Was very awkward but after a minute or so of talking to my flatmate and mum, I felt kind of at ease!
Then the other four flatmates came one by one within an hours space, met them all while they were unpacking in their room.
For the night though, we were doing shots and invited the next door flat over for a house party! Oh yeah and one of my flatmates threw up outside, hahaha.
To sum up, it's a very nervous moment, but once you get over that 'barrier', then you will feel at ease.