Product review (5 stars): OEM gasket fits well.  Installation possible for do-it-yourself.
This review is being written 3/15/2016 for the Samsung DA63-06542A Refrigerator Door Gasket by Samsung, advertised and sold on the Amazon web site.

This is the OEM gasket that fits on either the left or right side of some Samsung French door refrigerators.

Installation on the right side door is fairly simple.  Pull the existing gasket out and press-fit the new one into the groove.

For the left side, removal of the movable flapper/hinge is necessary.  This is accomplished by:
- Pry the two screw cover caps off of the middle hinge using a small flat-blade screwdriver
- Using a high quality PH0 Phillips precision screwdriver, remove the two screws.  A larger shaft screwdriver won't have enough clearance, and a low-quality dollar-shop style precision screwdriver might not allow enough torque.
- Slide the whole assembly up to disengage the lower and upper hinge points
- Gently pull out slightly to reveal the electrical plug connector behind the middle hinge and squeeze to disconnect
- Remove the old gasket and install the new one as for the right hand side door
- Install the flapper/hinge assembly

The design has somewhat of a weak point in that if one opens the left hand side door first, some stress is applied by the flapper hinge on the leading edge of the right hand door gasket.  This tends to make that thin part of the gasket crack over time.