Also among Bioware games:

Star Wars: Knights of the Old Republic

Star Wars: Knights of the Old Republic II: The Sith Lords

Jade Empire: Special Edition

Or you could emulate one of the earlier versions of the game (or even try to get the game on older hardware).

With that said, note a few things:
* It's a JRPG, whereas the first post didn't list any JRPGs.
* I honestly think its predecessor, FF5, is a better game.
* Many of the games listed in the OP have class systems. FF6 does not. FF5 does have a job system, which is an interesting variation on the character class system, so if you're going to recommend a FF game, FF5 might be a better choice.

The Temple of Elemental Evil

Since you listed non cRPGs, I'll list a few:

Gothic 1 and especially 2. By golly those are amazing.

Eye of the Beholder 2 (it's in some collection here on gog).

I could list some truly spectacular games if you were into jRPGs, but your OP doesn't seem like it, so I shan't.

But maybe not this one.

Magic Candle
Dark Heart of Uukrul

Actually, in Daggerfall, the Stealth mechanic is *not* optional. Through normal play, the Stealth skill, which is passive, will increase, and there's no way to turn it off.

(Incidentally, the Dodging skill also has a similar issue; it decreases the chance of your attacks hitting, and there's no way to prevent it from increasing. At least it no longer has this effect in Battlespire, but that doesn't help Daggerfall players.)

Check out Mary Skelter. It's a good game but not that well known.

Here are some more to add to the list. Some are already well known.

Fallout
Fallout 2
Fallout Tactics
Fallout 3: Game of the Year Edition (All Add-on packs included)
Fallout: New Vegas Ultimate Edition

Shadowrun Returns
Shadowrun: Dragonfall - Director's Cut
Shadowrun Hong Kong - Extended Edition

UnderRail
Underrail: Expedition (Base game required)

Wasteland 2 Director's Cut Digital Classic Edition

ATOM RPG: Post-apocalyptic indie game
ATOM RPG - Supporter Pack (DLC - some useful items, but not essential; mostly if you want to show support for the dev)

Stellar Tactics (InDev - but very playable and excellent dev support on forum)

Dungeon Siege Collection
- Contains: Dungeon Siege I, II & III (Does not include DLCs for 1 & 2)

Titan Quest Anniversary Edition
Titan Quest: Ragnarok (Base game required)
Titan Quest: Atlantis (Base game required)

SpellForce 2 - Anniversary Edition

The Incredible Adventures of Van Helsing: Final Cut
- Contains: The Incredible Adventures of Van Helsing - Complete Pack, The Incredible Adventures of Van Helsing II - Complete Pack & The Incredible Adventures of Van Helsing III

Druidstone: The Secret of the Menhir Forest (Not you typical RPG for skills & combat)

Neverwinter Nights: Enhanced Edition (Includes Neverwinter Nights Diamond, original game) (Paid DLCs also available)

Tower of Time (Not your typical RPG for combat mechanics)

Realms of Arkania 1+2 (Old school RPG)
Realms of Arkania 3 (Old school RPG)

There are more I can list, but it's dinner time. :)
.

OP is in australia. Game is region locked so we can't buy it/even see the game page.

Oh, sorry to hear, why is locked?

Darklands
Dark Sun: Shattered Lands

I'll +1 https://www.gog.com/game/prey As it is amazing and will be likely be greatly enjoyed if you enjoyed the Ultima Underworlds, Arx Fatalis and System Shock.

I'll also +1 https://www.gog.com/game/shadowrun_dragonfall_directors_cut and https://www.gog.com/game/shadowrun_hong_kong_extended_edition
Both are fun isometric strategy RPG's in the sci-fi/fantasy cyperpunk world of Shadowrun. All the Shadowrun games are self contained storylines and thus can be played in any order.

https://www.gog.com/game/legend_of_grimrock_2 is a very fun homage to the first person Dungeon RPG's of the old days. It's set on an island with some great eye catching scenery. And has puzzles ranging from easy to devious. You can create four party members of various classes.

Oh and I note that you mentioned Return to Krondor, have you played the original https://www.gog.com/game/betrayal_at_krondor
The first game is still an amazing experience with a fun script and battle engine. The word puzzle treasure chests are still something I enjoy each time I replay. The overworld engine does show it's age though.

Hey guys, thanks a lot for your suggestions and input. I've read all the posts and didn't expect to get this much of a response, so I'll post below the games I already have that you have suggested, and the games I will endeavour to check out ASAP:

Games I already have:
Lands of Lore
Die By The Sword
Titan Quest
Legend of Grimrock
Planescape Torment
TOEE
Divine Divinity
Divinity Original Sin
Mount n Blade / Warband
Wizards and Warriors
Pillars of Eternity
Pathfinder Kingmaker
Grim Dawn
Avernum series
Geneforge series
Tyranny
Grimoire HOTWE
Witcher 1-3
Wizards & Warriors
Most Arkane Games - Dishonored/Prey
Neverwinter Nights EE (Couldn't work out how to play this, I need to educate myself on how to roll stats and actually play)
SKOTOR
Jade Empire
Gothic 1-3
Eye of The Beholder
Morrowind/Oblivion/Skyrim/Daggerfall/Arena
Fallout series
Dungeon siege series
Spellforce 1-3
Incredible adventures of van helsing
Realms of arkania series

Games I will try:
Nox Archaist
Quest for Glory
DnD: Ravenloft series
Wizardry Labyrinth of Lost Souls
Stonekeep
Legends of Amberland
Ishar Compilation
Age of Decadence
Elminage Gothic
Deus Ex - HR
Ghost of A Tale
Magic Candle Series - Does anyone have a link for this? I couldn't find a page for the series? discontinued?
The Dark Heart of Uukrul
Darklands
Dark sun: Shattered lands
Prey
Druidstone

Games I'm not interested in:
Disco Elysium
Greedfall
Freedom Force (not into superhero / marvel stuff)
Driftmoon
Final Fantasy Series
Elex
Mary Skelter (not into JRPGs)
Shadowrun series
Underail
Wasteland games
ATOM RPG
Tower of Time

If you have any more suggestions, feel free to add them in, I have a lot to try now and won't say no to more!

Its abandonware. Try DJ Oldgames.