It depends on what kind of person you are. Coolness factor is important. You need to bring all the things to boost up your social status and leave home things that doesn't.
Those are what you should bring:
TV, DVD players, A/C, video game console, stereo, couch, table(for playing cards while drunk), bong, weed, beer bottle opener, most of your CD and DVD collections. lots and lots of posters
Since that is a lot of stuff, you need to locate and buy a loft. You can find those easily on campus.
Things you shouldn't bring:
Any instruments that is not guitar, especially violin/cello. Any books that are not text book, especially bible. Porn. CD collections contain lame music...classical and jazz music are no no. I can't think of anything else at this moment, but use your common sense. Don't bring things that lower your coolness attribute. Don't bring any of your high school stuff, like letter jacket or year book. That is very stupid.
If you want people to go to your room and hang out a lot, just do what I say. You want as many chicks to be in your room as possible. Don't bring anything too valuable. You need to feel comfortable with people in your room while you are not there. The worst thing you can do is to kick people out when you have to leave. You need to be ready to give up your privacy. Having too much privacy or being too territorial is uncool.
That is all I can think of.... I was in your boat not too long ago. I still remember how it felt.