Anyway. for me back on topic to this thread.
Personally, I would like to rename the Barbarian, Cleric (or split it into classes), Druid, Monk (or split it into two or three classes), Paladin (or split it into two classes) as well as splitting the Rogue into two or three classes.
Barbarian: I would say Berserker, but I like Berserker as a subclass
Cleric: Split into Priest and Templar (or either Warrior Priest or Holy Warrior)
Druid: Personally, I would rename Shaman (in the general anthropological sense that it is used among many anthropologists) and grant subclasses (e.g. Dreamwalker, Psychopomp, Skinwalker, Spirit Binder (for those cultures in which the collection of spririts is a reflection of power), Spirit Healer (someone dedicated to channeling a spirit to heal), Spirit-Ridden, etc.) at first level. In addition, I allow the character to choose from an ancestral, environmental, or totem spirit that scout and provide a limited version of the Guidance cantrip (History, Medicine, Nature, Survival), that requires a short rest or long rest for an answer depending the subject is not part of the spirits area of knowledge.
Paladin: Split into the Champion (a non-spellcaster with abilities refective of and fueled by his or her Oath) and the Holy Warrior with specific powers reflective of his deity and its domain).