I have to agree with Rudi about Hyatt rates. Almost without exception, for comparable properties in the same city, Marriott and Hilton will be less expensive - sometimes significantly less expensive.

In terms of earning awards, Hyatt may be good, but nothing beats Sheraton. As a regular member (no elite status) you get 2 points per dollar spent (3 if a gold member). It only takes 3000 points to get a free night at some properties, so for a $100/night room you can get a freebie in 10-15 nights. The only problem with Sheraton is that their standards are not nearly as high as Hyatt, Marriott, & Hilton. In some cases it is really pot luck with the quality of the property.