This will not be an exhaustive list like the other one, since to mention all the artists that come close would be far too difficult for this one blogger. Instead I'll just name off a few that I think are important, and will likely do further such posts down the road.
Asmorod - Dance in the Winter FogI've always wished I could put this on the list, since it is a personal favorite of mine, and I feel that it is criminally obscure. Still, there are other works which have a similar amount of metal, sometimes less, which I've said no on, so I need to be just about it. But this demo tape is fantastic, lo-fi, grimy, catchy, sloppy, mysterious, and both the black metal and dungeon synth parts are top notch. I listen to this work all the time and it never seems to get old; I highly recommend it.
Ildjarn - Hardangervidda
Strange and serene, this album is one of the best musical interpretations of nature that I've heard. At first glance, it might seem that this album could not be more dungeon synth, being a fully-synth work from a previously black metal artist. Still, to my ears this is not fantasy music, it is nature music, and I mean that about the music itself, not just the themes revealed in the titles. In that way it has a lot more in common with the "ice-landscape" sort of ambient music that is also closely associated with black metal (as well as general ambient and even new-age stuff). I do love this album, and recommend it to all dungeon synth listeners, however I think it is just not quite the same. This is one of the albums that I've put on and taken off the list several times, so if anyone else has an opinion on whether it is dungeon synth, I'd love to hear it in the comments.
Nearly Everything by Summoning
Obviously the reason Summoning is not on the list is because it's equal parts black metal to the dungeon synth. I'm assuming I don't need to say much about these guys, since all of you reading are no doubt already long-time fans of these metallic Tolkien symphonies. If you are reading this blog and don't know about Summoning, what are you doing with your life? Immediately get their entire discography, apart from Lugburz, unless straight black metal is also your thing.
Akhenaton - Divine Symphonies
Since starting the blog, this album has been recommended to me several times. I did not know of it beforehand, however after many listens, I have to say that I do quite love it. It is a fairly unique mixture of synths and black metal, nearly half of each. Because of that I can't say it is fully dungeon synth, but I still strongly suggest that everyone with an interest in the genre check it out. It is very dark, mysterious, and ancient sounding, and the synth moments are masterful, to the point that it might be worth listening to even if you dislike black metal. If not for being fair to the countless other symphonic black metal works, this would most definitely be on the list.
Godkiller - The Rebirth of the Middle Ages
Sounds almost like a mix of Summoning, Sacramentum, Satyricon, and early Burzum (at least with the vocals). Some thrilling and energetic symphonic black metal, heavy on the synth, of course, though probably the most black metal thing I'm recommending in this post. It is not the most original work, by any means, but everything is done well; it gets straight to the point, evoking both the frenetic violence of black metal as well as the epic awe and atmosphere of dungeon synth.
Nest's Entire Discography
Here's another group that has been on and off the list several times, which I really do wish I could call dungeon synth. It's very close, I think, but just not quite. It's a Finnish ambient group that is heavy on the harp and synthesizers, evoking moods of a dreamlike, primordial, pre-civilized world, where mankind was thoroughly entrenched within its biological place amongst all the other life-forms of earth. For that reason, as nostalgic and fanciful as it is, I still think it is slightly more nature ambient. BUT, Nest is one of my absolute favorite bands, and I believe that all listeners with a strong interest in dungeon synth will love them as well, so I wish all of you will check out their works. Fabled Lore is probably the closest of their material to the dungeon synth sound, however I would suggest starting with Trail of the Unwary, since it is their most deep and dreamlike work in my opinion.
But these don't even scratch the surface when it comes to music that is close to dungeon synth. I will be making quite a few more of these posts in the future.