A hotel chain's Best Rate Guarantee (or equivalent) can make or break a brand. While different hotels have different Best Rate Guarantee policies, I have had some successes with Hyatt recently when I was shopping for rooms at the Grand Hyatt Melbourne where I might be staying in a month or two. Hyatt guarantees the best rate when booking directly with them and they will match a lower, qualifying rate published on another site before beating that by an additional 20% - remember you will still earn your elite qualifying points and nights this way! While it isn't always easy to find a lower competing rate elsewhere (since the terms of the booking have to match entirely), it isn't at the same time, impossible.