My wife and I enjoy playing Diablo, Diablo2, Dungeon Siege & Dungeon Siege2
I enjoy Oblivian, but it isn't multi player.
Is there any new games simular to that style that we can play together on home network?

neverwinters nights 1 or 2

Yes, you should try Neverwinter Nights 1 and 2. You can play through the official  campaigns either alone in single player or together with your wife in multiplayer mode.

thanks I will give them a try...