Hilton is pushing forward as the best hotel point wise in 1Q 2012, especially for weekend stays. Their first promotion is:
Make every night you stay count for more. With the More Points promotion from Hilton HHonors™, you can earn 1,000 Bonus Points per night plus an additional 5,000 Bonus Points for every weekend* stay of two nights or more at participating hotels and resorts through March 31, 2012. Now, you can earn more points while having an experience worth sharing.
Sign up here
5,000 bonus points for a weekend stay is pretty awesome and will beat out the double and triple points that others chains are making for most people.
The other offer they have is 2500 bonus points for booking a weekend stay if you book it on January 17. So if you have weekend travel planned, it would be worth your while to wait until the 17th to book it. As far as I can tell these two promotions should stack giving you 2,500+5,000+1,000+1000=9500 bonus miles on top of the normal miles you will earn. Not too shabby!
Here is the link for the RSVP on facebook which it is looking like you have to use to get the 2500 bonus points.