Use Terminal
Type 'man -k zip' (without the quote marks). This will give you a short listing of the functions available for the zip utility.
At the bottom of the list you'll find zipinfo which is a command to list the contents of a zip archive.
For example: Let's say you have a zipped file in your Documents folder named myfiles.zip
Start Terminal and type 'ls' (no quotes again and not for the remainder of what I'm explaining)
You'll see a listing which includes Documents. Type 'cd Documents'
Type 'ls' again and you should see your file myfiles.zip
Now type 'zipinfo myfiles.zip' and you'll have a listing of every file in the zipped archive.