My favorite set has to be my Standing Liberty Quarters, even though I'm only 3/4 of the way done with them.
Nothing like the feel of a nice big silver half in your hand, wish they would go back to a large Dollar coin. If the Morgan/Peace/Ike was still around, it would be that. It would be very interesting to see how popular a clad version of the American Eagle would be in circulation... Regards, Darryl
I'm going to say halves, even though I don't really US coins (my "theme" is world coins 1550-1830, with some roman republican denarii + indian thrown in). I've got two nice early ones...
Of the modern coins I like the modern gold commemoratives best. I don't have anything close to a complete set, and probably never will. But I like some of the designs, particularly the 1987w constitution and 1988w olympic gold commem designs, even though they are quite common.