Both. ;)

But if you are limited by that pesky thing called money, then it depends on what you want. Baldur's Gate is a very solid, traditional RPG with your standard high fantasy fare (which is by no means bad, as Yahtzee said when reviewing DAO there is nothing wrong with that, and it does it well). Baldur's Gate 2 pretty much takes what Baldur's Gate had and expands on it, noticeably in expanding the interaction with your NPC companions, giving them banter and such so they actually feel like real people, and the quests has that perfect balance between sandbox freedom and strong story. It is epic.

Planescape Torment on the other hand is more dialogue-focused. The story isn't an epic mission to save the world but a more personal one, one that takes you across the planes. PS:T is the game where choosing wrong in a dialogue CAN have consequences. Also, your stats actually influence what you can say, and with the importance of dialogue in the game having high charisma to be able to convince people and a high intelligence to know what you are saying with a high wisdom to know when to say it is often more important than having a high strength to go "Nameless One smash!"

In short, Baldur's Gate 2 is a damn good game of D&D as you have always wanted it to be run, even if you're not a fan of typical D&D stuff it draws you in, while Planescape Torment is a damn good game of White Wolf RPG but using the D&D system instead.