Its a bit unfair to say the good expansion of NWN1 outclasses NWN2.... besides the good expansion of that game.
Each game had a good expansion.
And judging games based on mods is, eh.
Id say NWN1 has better modding tools and a more active community.
But in terms of party based gameplay, NWN2 wins. So id say NWN1 for multiplayer, NWN2 for singleplayer.
Especialy since NWN2 has the entierty of BG1, IWD1 and Pool of Radience as Modules
