Simply Hired - This search engine currently has more than 5.5 million job postings that have been aggregated from thousands of other websites.
Creating an account allows you to name and save searches, save notes about job listings and receive email alerts. You can block specific companies or sites from showing up in searches, which is nice if you don't want your current company to know you're in the job market.
Be sure to check out Simply Hired's Special Searches. There, you can focus your search on companies that are friendly to 50-plus workers, dog lovers, moms, veterans, new graduates and more.