You asked just a couple of days too late.
I completely cleared my wishlist two or three days ago. It had 92 entries on it. I decided to be totally focused on finishing games I started and abandoned, which is a pretty long list (Alan Wake 2, Death Stranding, Horizon Forbidden West, Resident Evil 8, Dead Space remake, and more) and also tap into my rarely touched VR library.
I could not tell you what game was on there the longest. More than half were of the "coming soon" years ago variety, but that's the best I can remember.