Reading through the posts, it seems there are many options, but a major question is how do you wish to use your mileage/points. Would you rather have HHonors points/ Starwood points, etc. Which will you get the most use out of. If you are looking to transfer to a airline program some of these are better than others, check their websites, etc. and figure out how points/miles transfer.

Hope this Helps--Loren