Were you good in Chemistry in school? Try (CHEM1011), Physics? (PHYS1121/1131), Bio? (BABS1201), Finance (FINS1613), Economics (ECON1101), Design? (See COFA handbook) etc.
Go with something you're interested in. There are heaps you could choose from. A lot of computer science student have different first year electives. After you've completed first year, you can do other Computing subjects as electives and quite interesting ones as well!
Last year I did history and it was awesome, the lecturers were good, interesting topics and it was just balanced.
I did political science also and I hated it. Looking back, I even wondered why I picked in the first place LOL. I did psychology also but it was just too much theory, and it got a little bit dry afterwards.
Heres a list to all the course at UNSW:
http://www.handbook.unsw.edu.au/vbook2015/brCoursesBySubjectArea.jsp?StudyLevel=Undergraduate