Whether you choose Hard Rock, Palms, MGM or somewhere else I'm sure you'll find people to talk to and have a great time.
One suggestion though from a parent that took 21-23 year old sons to Vegas.
Keep your ID in your shirt pocket - you will use it often!
For Room rates and more ratings take a look at
www.cheapovegas.com
Their descriptions are pretty accurate. For room rates I use
www.travelaxe.com - you do need to download their free program to use it.