Iain_Coleman
Explorer
Bad Dips
Wizard
Druid
Bard
Ranger
Paladin
Monk
Now this isn't to say there aren't multiclass combinations that work even with the bad classes, but there's generally very little reason to dip into any of the above classes I've labeled as Bad Dips.
I don't know, a two level dip into Divination Wizard to get portent can be awfully tempting, and three levels in Lore Bard can do a lot for a Charisma based caster.