See in the world of 5e as I've experienced it so far (which is not as much as I'd like), if I was to dream up an ideal party there would be 2 sets, one as a player and one as DM.
DM:
4 Player - Barbarian, Life Cleric, Sorcerer, Ranger
6 Player - Barbarian, Life Cleric, Sorcerer, Ranger, Rogue, Bard
8 Player - Barbarian, Life Cleric, Sorcerer, Ranger, Rogue, Bard, Fighter, Druid
Barbarians make exceptional tanks and with Unarmored Defence, they are a force to be reckoned with, mobile and dangerous, stealthy too.
Life Clerics can now wade into the combat to save wounded friends and heal from a reasonable distance
Sorcerers are well powered and can specialize in doing a lot of damage pretty easily.
Rangers are under powered but with a decent Dex and Wis, they can handle a share of the combat to keep the heat off of the casters, keep the party moving through terrain, allow for some pretty great open world encounters, you can't discount how much an archer can help, and they can emergency heal a couple party members from 2nd level on.
Player:
4 Player: Barbarian, Life Cleric, Bard, Fighter (Eldritch Knight)
6 Player: Barbarian, Life Cleric, Bard, Fighter (Eldritch Knight), Wizard, Rogue
8 Player: Barbarian, Life Cleric, Bard, Fighter (Eldritch Knight), Wizard, Rogue, Fighter (Champion), Druid
I'm not going to explain all my reasons here for the sake of making this post reasonably brief, but can elaborate if you'd like.