Since I've been DMing since the dawn of time (yes I am that old!) and since I have always used a wide variety of settings I have to throw in my two cents -
First lets take a look at the current D20 settings as far as I know them:
Scarred Lands - my favourite fantasy setting at this time since it has a different, dark flavour. If you're into a setting that has a lot of melancholy and bitterness in it, Ghelspad is your continent. Termana is more of a wild bizarre ride (can't wait for the Blood Bayoo source book). Overall it is very well supported and has a lot to offer. If you're into moral ambiguity in a setting SL won't dissapoint.
Kalamar - incredibly well done setting with a very very good product support. Flavour wise it isn't to my taste as it really has nothing new to offer. But if you don't own a lot of the old gaming worlds (see below) you can't miss with KoK.
Outhbound - since I am an old Cutter I can only say that Outhbound has really impressed me with its ingenuity. Very colorful, very special. But it is really way off your usual fantasy setting. If you like Planescape this is a winner though.
Rogukan - Simply the best damn pseudo-asian setting ever done. If you want to run an asian-flavoured campaign this is where to look. Incredible.
Since I am sitting in the german diaspora I haven't seen the rest mentioned here.
Lets go to the old settings:
Harn - was there ever a setting that was as unsuccessful and still as good as Harn? If you want a low magic mediaeval setting this is where to look. I have all he modules and can only say that every serious DM should own this. This is the best!
Al Quadim - I own everything and still believe it is bad. Too much high magic and flashy stuff but internally inconsistent. If you're looking for something with an arab flavour go seek the old GURPS city book Tredroy by Wolfgang Baur. Very good city book with a lot of useful backround information.
Shadow World - anybody remember that? It is actually pretty good and Iron Wind is one of my favourite adventures of all time. A lot of useful stuff that you can simply use and drop into another campaign world since this world is so vast and fragmented.
I could go on but since you asked for D20 I'll stop here. My vote goes out to the Scarred Lands and Outhbound since they're really something different flavour wise. Kalamar is very well done but it's just an improvement on older settings.
First lets take a look at the current D20 settings as far as I know them:
Scarred Lands - my favourite fantasy setting at this time since it has a different, dark flavour. If you're into a setting that has a lot of melancholy and bitterness in it, Ghelspad is your continent. Termana is more of a wild bizarre ride (can't wait for the Blood Bayoo source book). Overall it is very well supported and has a lot to offer. If you're into moral ambiguity in a setting SL won't dissapoint.
Kalamar - incredibly well done setting with a very very good product support. Flavour wise it isn't to my taste as it really has nothing new to offer. But if you don't own a lot of the old gaming worlds (see below) you can't miss with KoK.
Outhbound - since I am an old Cutter I can only say that Outhbound has really impressed me with its ingenuity. Very colorful, very special. But it is really way off your usual fantasy setting. If you like Planescape this is a winner though.
Rogukan - Simply the best damn pseudo-asian setting ever done. If you want to run an asian-flavoured campaign this is where to look. Incredible.
Since I am sitting in the german diaspora I haven't seen the rest mentioned here.
Lets go to the old settings:
Harn - was there ever a setting that was as unsuccessful and still as good as Harn? If you want a low magic mediaeval setting this is where to look. I have all he modules and can only say that every serious DM should own this. This is the best!
Al Quadim - I own everything and still believe it is bad. Too much high magic and flashy stuff but internally inconsistent. If you're looking for something with an arab flavour go seek the old GURPS city book Tredroy by Wolfgang Baur. Very good city book with a lot of useful backround information.
Shadow World - anybody remember that? It is actually pretty good and Iron Wind is one of my favourite adventures of all time. A lot of useful stuff that you can simply use and drop into another campaign world since this world is so vast and fragmented.
I could go on but since you asked for D20 I'll stop here. My vote goes out to the Scarred Lands and Outhbound since they're really something different flavour wise. Kalamar is very well done but it's just an improvement on older settings.