Cavalary: If it won't be too hard to code or make it even nastier to work within GOG's access ban limits, MaGOG may be used for this? Since there are wishlist extension gogmixes now, there could be actual wishlist gogmixes, with either tags or set interest ratings. Tags would likely need to be formatted in a certain way and have a stricter character limit, so you won't end up with full comments from every user when browsing, would allow more freedom for users, but won't allow any ordering by MaGOG. Set interest ratings (say: highest, high, medium, low, lowest, none - MaGOG only reads the first word in the comment and ignores it if it's not one of these) would also allow the "wishlisted by" line to be sorted according to interest (only question being where to fit those with unknown rating in the bunch) and likely also make way for an option to not display those with interest below a certain level.
... And now I'm feeling awkward for making suggestions that'd just require someone else to do probably plenty of work.
Nah, adding Gogmixes just complicates things. I was just thinking of doing the same as I do with manual sort, create a dictionary (or an approximation as JS doesn't have the real thing) with the ids from your wishlist as keys. Then just store a comment or tag with each game when you wanted.
The extra bit is then sending this data back to my server so it can be loaded by others when
they view your wishlist too. But that just requires a username to be sent to the server and then checked against the held data and the tags returned if they exist.
Changed usernames might be an issue, but there's probably a way around that.
I probably wouldn't allow sorting by it as that would be more complicated to implement, but it would be a start.