War Cleric at lvl 1 grants you an extra main attack, so it's very useful for physical classes.
If you're looking strictly for gameplay benefits then either Ranger, Rogue, Barbarian or Fighter at 11 with War Cleric (1) is a great combo.
Personally though I started my current main character as a War Cleric (1) first for roleplaying/dialogue purposes and then just went into Fighter (6) and Rogue (5) multiclass. It's pretty great because in terms of roleplay I'm a jack-of-all-trades Cleric, but in terms of gameplay I am a Fighter/Rogue that hits like a truck and has more health than any of my companions
