I find the OE short shifter to be a waste, personally. There isn't much of an improvement in feel or throw length. Anyone who spends time in an online community will see talk of the aftermarket alternatives, and once they row through the gears in a car that has them, will be left wishing they hadn't spent the money on the OE version. If you're selling a lot of them, go for it, but most buyers who come online to research and asking about the OE setup will be steered away, so it will not be a "bargaining chip".
Armrest extension. As someone who's tall, this is key for me on long trips.
Auto-Dim Mirror (w/ or w/o HL)
Side Window Deflectors. I leave my windows cracked every chance I get. Having rain get taken off my "don't crack when ______" list would be nice.