I avoid Hilton since I have had repeated problems with them not awarding points. They also expired a huge number of points without warning. I know... my fault. However, their points expire way too fast. By comparison, Starwood re-instated a very large number of expired points for me once. In fact, it's one of the reasons I've switched my 50+ night business to SPG. That, and they have the absolute most gracious, wonderful reservation people in the business. When it comes to phone service Starwood even beats Onstar (which is damn hard to do).

In any case, I would choose IHG as a second. When travelling in the US, Holiday Inn Express is one of the best values around, with no absurd Internet charges and a nice free breakfast. Nothing fancy of course, but you can always expect a clean decent room with them.