We did a lot of activities that KSUViolet posted as well.

One of the best was always meeting on a Tuesday (or whatever day it was - I can't remember now, haha) in the student union for lunch.
We also had family nights which were really fun, and made Big Sis'/Little Sis' family trees (which eventually overlapped into other families), and watched movies.
Crafts were very big in my chapter and sometimes we'd have a craft night where one sister would show us how to make something (once it was fun Sigma bracelets with purple and white Sigma beads she'd made).
When Friends was still on we used to have 'Friends Nights' and all go over to a sister's house to hang out, have pizza or popcorn and watch. Such good memories. I think my favourite Friends night was when we got the whole chapter inside her house with the chapter consultant for a photo. We were packed in, but it was really fun.
Sigma Love,
Laura