I have a Starwood Preferred Guest American Express card and I am quite pleased with it so far. It is $120 per year, although you can often get the first year free. Anytime I have needed to contact customer service (which has not been often) their response time has been excellent and they are quite easy to deal with. SPG does not have blackout dates and Starwood have a vast array of properties to choose from at varying point rates. You also have the ability to transfer SPG points to many frequent flyer programs.
The card has a wealth of perks available when traveling including Car Rental Theft and Damage Insurance, Baggage Delay Insurance, Flight Delay Insurance etc. It also automatically increases the manufacturer’s original warranty for one additional year (basically doubling it in most cases) when you charge an item to the card. Amex also has pre-sale privileges and reserved seats for some concert events.
This really has sort of turned into an advertisement I suppose, but I really am pleased with it. Some complain that Amex is not accepted at a number of locations, however the only place that I would normally go that does not take it is Super Store, so I just go to Sobey's when possible. Just about every other business I deal with takes it (although I do seem to get a lot of odd looks when I use it, as I don't think Amex is terribly popular in Atlantic Canada).