1) Planescape torment - One might reference Neverwinter Nights games (specifically with the expansion stories) to get the isometric D&D style gameplay. But the gameplay in Planescape was not important at all, it was all about the protagonist's existential dilemma and top-quality writing, that's the element that people remember so fondly. With that in mind, The relatively recent game I'd recommend that you try is Walking Dead Season 1. If you don't watch the show, or read the comics, that's fine, because this game is both totally unconnected to, and is much better than the source material. Unless you're the kind of person that likes to jump on the bandwagon of hating things that are popular? This "game" has hardly any game mechanics to speak of because this is an RPG in the purest sense. You play a role, and the entire focus of this game is on making you really feel like you're IN the role. You make weighty decisions that result in significant consequences.
I own and played through all the four episodes of Walking Dead and quite like the game. I also replay Planescape Torment every few months. While Walking Dead is a good game, it is nowhere near Planescape in my opinion.
Writing is the only thing we will compare. Gameplay is quite poor in both games.
The vastly summarized premise of Planescape Torment: You are an immortal being, tormented for all eternity by losing your memory after every death. Your goal is to decipher the origin of your curse and find a way to finally die. Set in a world where thoughts and believes shape the very fabric of reality. Major question being asked "What is the nature of a man?" is quite deeply philosophical and is treated with great depth.
Contrast it with the Walking Dead: You are a convicted criminal. The goal is to survive in a standard run-of-the-mill zombie apocalypse. You come across a stranded child and take over the role as her parent. The major choices are how to earn the trust of others, how you treat others, how far you go to look after yourself vs looking out for others in a survival situation, making alliances and enemies inside a group of survivors.
Straight up, Walking Dead's writing just doesn't compare. Planescape deals with deep questions of philosophy and the meaning of life. In addition it also deals with same issues as WD: You have a very wide range of how you can treat your companions. Good example is Dakkon: He is your slave chained by his oaths. You can torment him about it, remain neutral or help him achieve the next level of enlightenment of his philosophy.
Decisions in WD are not really weighty. At most your choices result in a character being killed earlier or later. You never shape their development. No matter how badly you treat Clementine, you will still be there at the hotel rescuing her from the psychopath and you still will help Clementine get away from you when you turn. The only difference is if she shoots you or lets you become a zombie. You can't stop Kenny's wife from suicide no matter how you treat her or whether you volunteer to put down their son yourself. Moreover the game's writing quite simply lacks depth: I can finish it at relaxed pace in three days and there is no reason to replay it beyond three times or four times since the decisions are so limited and you will see almost all content by the second playthrough.
Contrast it to PT where my decision will dictate the very state of the plane of existence. I can also have a huge impact on the fate of the companions and their outlook on life.
There is simply no game that I know of that rivals Planescape Torment. It is a masterpiece of its genre.