Go outside, to the park, or just be happy you have a roof over your head.
chill with friends
Lots of beanbags and cushions, and just as many friends.
LAN party! Board game party! Well, if you're into that sort of thing.
Get together with your friends. Try and make sure there are one or two more people than you have space to seat. Have a few sodas or coffees. Watch movies you've all seen before a dozen times and eat popcorn until 3am.