doady: Custom content or not, the official content should still be great.
That's true for a new release, but 10 years after, with such an industrious modding community, it hardly matters anymore. I know plenty of hardcore NWN players who don't even know the "official content" because they never felt the need to try it in all those years.
Are you actually looking for suggestions? If so,
this would be a good place to start. :)
Darkenmal: If anyone suggests something, could they do a small writeup on why they like their favored RPG.. it would help decide for sure.
I definitely am looking up some of the RPG's now but I am a total noob when it comes to the old-school RPG.
No idea what to look for if you know what I mean.
Surely you must have
some idea what to expect from a RPG, what you are looking for in them (story, action, strategy, customization etc.), or what settings you prefer (typical fantasy, post-nuclear, steampunk etc.)? Which RPGs did you play so far and what did you like about them? It's easier to recommend something if we know your tastes.
Generally I would agree that Neverwinter Nights probably offers the richest co-op experience. It''s not just a game but a game creator that allows people to build their own adventures and even worlds and host them online. So you can either play through the original content or high quality fan-made story modules with your friend, or you can join a so called "Persistent World", a world to roam in, created by other gamers, with its own setting and rules etc. and join other people who play in that world. Or you can join a campaign with other players worldwide lead by an actual dungeon master who can react to your character's behavior and create encounters on the fly.
Of course you can also have lots of fun in single player mode. And there is so much custom content that almost everyone should find something they like, once they get accustomed to the basic gameplay of NWN.
On the other hand, if you're looking for a great story, in my opinion (and lots of others agree), that would be Planescape Torment. It's one of the best written games ever with an intriguing plot and lots of background info about an unusual and original setting. You might not like it though if you're looking for quick action because to properly enjoy this one, you have to read through a lot of dialogue. This is a purely single-player game.
Nox and Arx Fatalis are quite good games in their own way, more on the Action side and less story and reading, but good atmosphere and enjoyable gameplay. I think Nox had a multiplayer mode, not sure if it's still working though.
Lots of other good RPGs to choose from, it really depends on what you're looking for.