Most likely this one. :)

I did and I messed it up. :/

Muntdefems offers the correct link.

Added it to my gogmix. Thank you both!

Thanks both.

For the moment though, my policy is to only include manuals that GOG can actually put under "Extra Goodies" i.e. ones that come as separate files and not a webpage or a wikia. Shovel Knight is on the list, because according to this post
https://www.gog.com/forum/general/list_of_gog_games_with_missing_manuals_and_where_to_find_them/post85
there was such a file. Doesn't seem to be the case though with Specter of Torment.

Might as well mention it here: The map supplied with Might and Magic 9 has a small portion of it from the bottom cut. The full map is available easily on the net, for example here:
http://demilich.by/mm/maps/chedian.jpg

Won't create a separate entry for it, since nothing important is really cut off (see attached for what GOG's version looks like), but for pumpkin's sake GOG; you had one thing to do.

Update: It seems that the newly added Spellforce 2 Anniversary edition doesn't include any extras -and thus not a manual as well. So, for those that haven't bought the older games yet, I added it to the gogmix with links to their manuals.

According to Grargar the manuel is in the installation folder.
https://www.gog.com/forum/general/release_spellforce_2_anniversary_edition_74a18/post45

Correction: the game does include a manual for the Gold Edition in its installation folder (specifically the "docs" subfolder). Said manual is also accessible through a start menu shortcut. For those who don't want to install the game just to get access to the manual, I have uploaded it on my Dropbox account:
https://www.dropbox.com/s/y1sjbmdgn2fj5ha/Spellforce%202%20Gold%20Edition.pdf?dl=0

Edit: Ninja'd by my own post. :P

Thank you both for the corrections -when I checked Grargar hadn't posted yet (also thanks especially to Grargar for hosting the pdf on his dropbox). Modified the entry accordingly.
I also wondered what the difference between the Gold version and the Anniversary one is, and it looks that it isn't all that big (https://www.steamgifts.com/discussion/5Xi9I/spellforce-2-anniversary-edition-free-update-from-spellforce-2-gold), so I guess the manual of the gold edition is just fine.

Added Spellforce 2 to Appendix B.

Like the other two Double Fine remasters (Grim Fandango and Day of the Tentacle), Full Throttle Remastered offers no manual. The manual for the original version can be found below:
https://ia800401.us.archive.org/3/items/Full_Throttle/Full_Throttle.pdf

Well, I had already noticed the missing manual since the preorder, but figured I wouldn't post about it till the release (especially as afaik product codes change). And then the release came, and I just can't get the relevant entry created! I pick it, but it doesn't load the cover, and when I click save it doesn't save!
Before you posted I also had already found another source, with a colored manual, and other extras too (still, thanks for your vigilance on the subject), but I couldn't post it because of the aforementioned problem (and now that I checked again it still didn't work). I'll post here what I was going to post in the gogmix while waiting to see how that issue can be fixed:

Full Throttle Remastered
The manual of the original version isn't included. It can be found with other extras at http://www.mocagh.org/loadpage.php?getgame=fullthrottlewl (the manual itsefl is the cdcase-inlay)

Saints Row IV: Game of the Century Edition doesn't have a manual as an extra. Can't confirm yet if there is one in the installation folder, but for the time being, here is a link for it:
http://cdn.edgecast.steamstatic.com/steam/apps/206420/manuals/PC%20SR4%20Manual%20UK+INT+SCA%20zur%20Ansicht.pdf?t=1486042785

You're pretty fast! I just now saw this release. Your link eats way too many characters though (112 to be exact) - I found another link of the exact same manual (this one: [url=ftp://ftp.kochmedia.com/pub/hotline/deepsilver/SaintsRow/4/Manual/PC_Manual_EN.pdf]ftp://ftp.kochmedia.com/pub/hotline/deepsilver/SaintsRow/4/Manual/PC_Manual_EN.pdf[/url]) which is 82 characters, so I'll use that one instead...
Anyways, yet again the gogmix won't let me add the game until some hours have passed so...

And Saints Row IV has no manual even in its installation folder. Oh well...