Anomen
Anomen is a Lawful Neutral Fighter/Cleric (dual-class) who can be recruited in BG2.
Due to his initial class being a fighter, Anomen can place up to five proficiency points in most weapon styles, which gives him substantial bonuses to hit and damage. He is also a powerful cleric, and as such can be used either as a front-line melee fighter or a defensive healer. As a result, he's an ideal candidate for a good or neutral party, and I have used him in every playthrough.
Baldur's Gate 2
Anomen can be recruited at the Copper Coronet from chapter 2 onwards. He will initiate dialogue when you walk past him and will offer to join if you say you are courageous and a force for righteousness.
Anomen has a very short side-quest which begins soon after you recruit him and decides whether he later becomes a knight or not. Whichever way the quest is resolved, Anomen's alignment and statistics will change. Without giving too much away, it's better for the party if he becomes a knight.
Whilst he can be somewhat annoying and arrogant, Anomen does not have any major conflicts with other good or neutral companions, and can even get along with Viconia. He will object and possibly leave the party altogether if your reputation falls too low or you take an evil course of action when presented with several choices. Romance
If your character is female and human, she can enter into a romance with Anomen.