I played a lot of FreeCiv and had a lot of fun with it. Not sure if it's still dev/maintained

They do, but it's a very small part of their total financing (less than 1% I think), and they don't have government appointed staff or anything like that.

Are you trying the original or Enhanced Edition? I've had no issues playing the EE versions of Infinity Engine games on Ubuntu

This 100%. The only games I've managed to finish in the past ten years are on Switch or a portable system.

You beat the materia keeper without using materia!?

I loved Ogre Battle 64. To date, I can't remember playing anything else quite like it.

I can get behind the CC vs CT take. I finished CT first circa 1998 but found it pretty boring (I have a better appreciation for it now). CC was a lot more enjoyable to me--combat had a lot going on, and the music is an unmitigated masterpiece.

Putting DQ7 on here is almost a bit spicy, but I think it's one of the best representations of the series in terms of scope, pacing, gameplay, and storytelling. It's absolutely slow, but that was sort of the point.

Depends on what you like about EO. EO makes party building and finding synergy a core part of it's gameplay. For something like that, Star crawlers, Paper Sorcerer, and Wizardry 8 are good choices (7th Dragon series also falls under this, though it's not first-person).

If the mapping is what you like, I don't think there are any other games that integrate it into the game itself, but a lot of games expect the player to map using graph paper. For those, Wizardry 1-3 are good to start with as they are challenging but always fit on a 20 x 20 grid. Later Wizardry 5-7 are also very good but have larger maps that will end up going off the edge of the paper sometimes (though they tend to have more interesting combat too). Might and Magic III would also be a good choice if you want to do more than dungeon crawl. If you do try classic Wizardry, I'd recommend one of the console ports. Robert Woodhead (programming of Wizardry on Apple II) has actually said the Famicom version is the "best". I'd say the GBC or SNES version are best.

For something more modern but still like Wizardry, there's Elminage. It's a modern take on Wizardry from a dev that actually made a lot of Wizardry spin-offs. It has more interesting classes that classic Wizardry. Experience also has some modern takes on the formula (Undernauts being the most recent) but I have trouble getting past the aesthetics of them.

Finally, if you want something more tactical and don't mind AD&D, take a look at some of the gold box games like Pool of Radiance. Dark Heart of Uukrul probably falls in here too (but is not D&D). They have first person mazes, but grid based combat, sort of like a proto version of Tactics Ogre.

And my final off-the-wall recommendation is Legend of Legacy. It's not first person, but it has the same explore, map, and push your limit loop as a good DRPG.

I respect this, but always had trouble with portal 2. It has some great parts but is also way too long.