In BG2 you can easily put together an evil party, including neutral companions who don't care about the good-evil thing.

I would also note that a good person will care about the "goodness" of all their fellow party members, but the opposite is not necessarily true. So a good PC would not accept an evil companion, and possibly may not even be able to accept a neutral companion, whereas an evil PC won't really care about the alignment of companions so long as they go along with the PC's plans. So good PC and evil PC are NOT mirror images of one another with respect to roleplaying. As others have also noted, it is much, much more difficult and constraining to truly roleplay 'good' in a D&D/FR game.