same class combos are the easiest to get to grips with at least at the start. However, pretty much any combo can work so it's all down to what you do.

For example i did warlock/pally for a while and mainly had my pally healing so you could have the shaman take that role. or you could have them as two dps casters or.... as you can see there are so many options the only major advice for a starter is avoiding 2 melee chars as that gets awkward

As for funnest? try it and see