Convince me guys!

I don't know where to start, there is just so many to choose from.

Co-op that I can hook up with a friend would be a huge plus.

Graphics don't really bother me, unless its in that ugly transitional area of 3d.

Help me out here! :)

I don't know. the best ones I can think of all aren't co op. My favorite ones are Planescape: torment, fallout 1 and 2, and Arcanum. Planescape: torment is a lot of reading so if reading a lot annoys you, it may not be your kind of thing.

Fallouts and Arcanum are games that probably have the best role playing in any video game if you're looking for role playing as whatever type of role in a fictional setting. I mean with being act as a diplomat, thief, fighter, scientist, or other things...

Two words: Arcanum.

Baldur's Gate 2. It is arguably the most balanced experience in terms of combat and dialog and has some of the best characters in an RPG.

I'm not biased at all, honest.

I found NWN as a whole to be a bad RPG, I know it's not a popular opinion but the game is just so linear, I mean it even has cut-scenes which aren't movies. I forgot I was even playing an RPG at times, and thought I was just collecting points on a standard hack and slash game from beginning to end.

But yeah seconding Planescape, also Arcanum and Baldur's Gate/s, those games give you a nice feeling of freedom and being actually able to "role play", and not be dragged along some generic straight-forward plot.

Also, Arcanum is set in a very unique and original take on a fantasy world.

OP, don't mind Frater's counting, he's otherwise correct!

Isn't "Arcanum" a portmanteau of "Arcane" and "Sanctum"? If so it could be two words.

Quite possibly! Anyway, it was a little Brass Eye reference, so I wasn't expecting you heathens to get it anyway!

Fallout + Fallout 2 are the ones to get. (Specially with the mods+fixes). This is followed by Torment and Arcanum (again check for fan fixes).

For coop I don't know.

I found Neverwinter Nights multiplayer to be the closest you can get to a P&P RPG. Don't let the "NWN story stinks" comments discourage you. Not that they're wrong, mind you :p but NWN is all about the custom content, and there are a lot of really superb modules with a truly professional quality.

Which modules?

I've owned NWN for a decade but I've only played the official content. I've yet to try any of the custom content, lol. Custom content or not, the official content should still be great. Actually, I thought the expansions were pretty good, much better than yhe Original Compaign, but still a far cry from true classics like Arcanum or Baldur's Gate.

Speaking of Baldur's Gate, I imagine it is very fun for LAN parties as well.

Of all the games I've played that are available on GOG, I think Baldur's Gate 1 and 2 are the best, followed very closely by Might and Magic VI and Arcanum. I haven't played Planescape yet so I can't comment on that.

Baldur's Gate 2 is a masterpiece.
But play Baldur's Gate 1 first and transfer your character.

The Might&Magic games are also very good.
If you are not adverse to mapping, start with MM1.
If you are not adverse to EGA graphics start with MM2.

Fallout 2, Fallout 1, Planscape Torment, Arcanum.

In that order.

Don't get all the hate for Neverwinter Nights, personally. It might not be as good as Baldur's Gate/Icewind Dale in a lot of ways (always found the party system somewhat clunky, not as tactical as aformentioned games) But it did a lot of other things right, and the toolset is nice, lets you make and play player created content much easier. As for the campaigns...well, I thought Hordes of the Underdark was decent enough.

Best GoG crpg? Arcanum and Planescape Torment are both excellent, and are pretty unique while the gameplay (esp combat) can be rather clunky at times. On the other hand, Baldur's Gate is a bit more generic but a bit more polished as well in most regards. I find BG II's controls rather intuitive and easy to learn and use. Go with those first before branchign out into Neverwinter Nights or Icewind Dale.

On another point, judging by your avatar, you might want to keep an eye out for the Wheel of Time rpg that Obsidian is working on, assuming that it hasn't been cancelled yet.