1) A sleep mask
Never in my life have I wore a sleep mask. Even on airplanes. It was only after like the first week of living on-campus where I was like "Yeah, I'm gonna need one of those sleep mask thingies." Luckily for me, my parents used to work for a pretty big company that would send them on business trips semi-frequently and they got to fly in business class. So they had a major abundance of those complementary airplane kits with the toothbrush, mouthwash, comb and of course, a sleep mask. This may be different depending on the people you room with. Since I was placed into overflow which is where they take a study lounge and fit 6 people including myself in there for a semester, there was always someone using their laptop or had their desk lamp turned on. I didn't want to bother them so I figured a sleep mask would be the perfect solution and sure enough, it was.
2) Water boiler
Ok so technically its against the rules to have water boilers in dorms at least in my university. But hell, you're bound to break the rules sooner or later. Plus it is just too useful to ignore. Whether you're slurpin ramen or brewing tea, you gotta have one of these things. Lol every time there were dorm checks we would hide ours inside a drawer or something like it was booze.
3) Mini vacuum
Again, this may depend on the people you room with and how tidy they are but since I was rooming with 5 other people and I'm kind of a neat-freak, I got me a mini vacuum and used the hell out of it. This obviously goes without saying but if you don't clean your room you're bound to attract uninvited guests like roaches and rodents. The amazing thing was that even though there were 6 of us guys living in the room, we never had any encounters with pests. While the entire hall itself had dead roaches and a rat problem. Some university halls will provide their own vacuum cleaners that you can rent out but they either suck (lol like they're terrible), or are just too inconvenient to get.
4) Multi-tool
This is IMO a lot more useful than bringing like a single knife. I've got a fishing multi-tool that is basically a folding pair of pliers with a knife, scissors, screwdriver(s), file and even a freaking miniature saw. You never know when you're going to need one of these things for example one of my roomates was experiencing some problems with his laptop charger. I busted out this little beast and opened up his laptop and quickly diagnosed the problem as a faulty port connection and a dead battery. Now later on I decided I'd buy a dedicated toolkit with all the bits and stuff since I was upgrading my laptop's storage but the multi-tool would've worked just fine on its own.
ADDENDUM
Alright so right after I posted this I remembered something really important. Its something you should not bring to your dorm either because its too big of a hassle to move or you'll just end up not using it at all. So one of my roomates bought his monster gaming PC which had to weight almost 20+ pounds. How do I know this? BECAUSE I WAS THE UNLUCKY FUCK WHO HAD TO HELP HIM MOVE IT OUT. In the 4 months we've lived on-campus, he only used that thing a grand total of 6 times and only 1 time for actual gaming. I shit you not. And the thing is, HE ALWAYS WENT HOME DURING THE WEEKENDS. Later at the end of the semester he admitted bringing that thing was a terrible idea. He also had a pretty large gaming monitor which probably was fairly heavy itself.
So I highly recommend that that you just bring a laptop as that'll be a hell of a lot easier to move around. If you still want to game on a PC, just invest in a decent gaming laptop.