There are warehouse positions in Costco as well. Costco seems to skirt labour laws a little less than other retailers.

I worked at UPS as a package sorter/loader/unloader. The money was great and the part time position offered pretty good health and dental benefits. Only issue was the job was hard on my health. Weird hours and repetitive motion can tear your body to shreds if you let it. But the hours were consistent and there were plenty of opportunities to make extra money during the holidays.