Cash back is at 200 points to the dollar or 0.5 cents per point. Gift cards such as some of those found at
http://www.membershiprewards.com/Cat...n.aspx?clgid=3 are 100 points to the dollar. Some of retail including some cards are at 200 points to the dollar so beware.
Some very high end retailers like ESCADA offer $1,000 certificates for 100,000 points. That would buy a cute purse and maybe a pair of jeans. Saks also has a $1,000 certificate.
Don't rule out airline tickets. Where you have American Air points, Amex points offer you other choices as well. There may be places you want to go and cannot get to with American. Assuming that a business class ticket is usually worth $3,000 to $8,000 even if you have to use 160,000 to 250,000 each, you get more than 1 cent per point in value.
Consider gifting tickets to friends and family. You can collect friends in a hurry that way.
Good luck.