Invisible Inc. is a great original game, but hardly a RPG, it's a Stealth Roguelite.
I don't remember Drakensang series had stealth, and I agree its not really iso like or top down. But Drakensand series is a good one particularly River of Time. Also Shadowrun series has no stealth system, nor Spiderweb games.
The problem is stealth and party is hardly compatible, and DOS achieves it truly because of party slip and a token allowing teleport a part of party to the stealth character. Other with party and stealth system use stealth for a much more anecdotal usage, mainly to start combats or avoid a few combats, plus sometimes few rare small parts designed for some stealth progression but nothing noteworthy.
With a stealth system, but a rather limited use of stealth:
- Tyranny
- Baldur's Gate Enhanced Edition 1&2 (it's a rehash, the true releases are about 20 years ago, but in term of production level it didn't aged that much in my opinion)
- Pillars of Eternity
- Sword Coast Legends (yeah in my opinion it is cool to play, will be more limited in term of choices on how achieve goals)
- Torment tides of numenera (very special which can be a positive or negative opinion, depending of player)
With a possible but non mandatory heavy usage of stealth and beside DOS, I see only few indies RPG:
- Eschalon Book series (indie, and even an expert could play full stealth the full main story without killing anybody for one of the book, and only very few kills for others)
- Underrail (indie, great one until very weird last parts, stealth is real time outside of combats)
- Antharion (cheap indie but very cool in my opinion)
- Balrum (cheap indie but cool to play in my opinion, no true stealth system but allows an heavy usage of sneaking through noise&light systems + night&day cycle, so it's a sort of natural stealth system)
- Templar Battleforce (indie, and not truly a RPG as it's a Tactic RPG, but it has a real stealth system, your choices will be mainly how you achieve the missions that are mainly combats, it is quite borderline to qualify to all criteria, but I found it very fun and it uses a stealth system so I can't resist add it in the list)
If some sneak through parts without stealth system apply then there's also:
- Wasteland 2
- Dragonfall (I don't remind that Shadowrun Returns applies, and for Honk Kong I'm a lot more skeptical plus it has some real time action parts)
- Avadon trilogy (indie, real time sneaking, but Avernum series from same dev don't have any sneaking parts if I remember well)