Mesmer or Necromancer [Alt]
It depends on how you want to play. Both can be good support if you want that. They can both do good damage too if that’s your style. I leveled Mesmer first and prefer it to Necro. Nothing wrong with them I just prefer the more indirect play style of Mesmer.
Ironically I think mesmers are better if you are thinking of a minion build. Our illusions are meant to be throw away and have appropriately short cool downs. My experience with Necro minions is that they last a wee bit longer than illusions, but have longer cool downs.