My "ideal" party...that is fairly specific/on table to table, play style, type of adventure/feel of the game, personal preferences and a whole lot of other arbitrary variables. I suppose mine would go something like this...
For 4:
As written, I guess Fighter, Cleric, Rogue, Wizard. Though I would hate to run a game with such a small party.
For 6:
Fighter (Champion), Dwarf
Fighter (Battlemaster), Human
Fighter (Eldritch knight), Elf
Wizard (homebrew a generalist), Human
Cleric (Life or Light), Human
Rogue (Thief), Halfling
For 8:
Fighter (Battlemaster), Dwarf
Barbarian (Berserker), Human
Fighter (Eldritch Knight), Elf
Wizard (homebrew generalist), Human
Cleric (Light or Life), Human
Rogue (Thief), Halfling
Ranger (Hunter) or Cleric (Tempest), Half-Elf or Human
Rogue (Arcane Trickster) or Druid (Land), Gnome or Human