If you care about free nights, I would not choose Hilton for your NA business. For the next three months Hyatt is running their "Faster Free Nights" or FFN promo which usually happens once or twice per year. You will earn a systemwide free night certificate for every two stays on top of the normal (generous) point offerings. One downside of Hyatt is that they tend to have fewer international properties. Having said that, many of the properties they do offer internationally are great hotels (check out the PH Paris).

If you don't go with Hyatt, I would choose Starwood. They have great presence in Europe and Asia (better than Hilton IMHO) and top-notch hotels. You can also convert Starpoints into M&M points at very favourable conversion rates (20,0000 : 25,000) if you find yourself in need of additional airline miles.

As a third choice, in your situation I would recommend IHG (Intercontinental Hotels Group) over either Hilton or Marriott. Much better promos/earning potential and great coverage in Europe.

The only compelling reason to choose Hilton or Marriott is if your business in NA takes you to a lot of small towns and/or rural locations where Hyatt and Starwood are non-existant. However, IHG has tons of coverage in these secondary markets and their revamped Holiday Inn product is pretty decent.

SG