Which diet is the healthiest?

Balanced omnivore diet-
Regularly eating meat, but also eating dairy, fruits, vegetables, etc. Maybe a little bit too much meat.

Balanced omnivore diet with less meat-
Basically the same diet as above except eating more fruits, vegetables, and more "vegetarian" foods, but also occasionally eating meat.

Vegetarian diet-
No meat but dairy, eggs and other animal products are fine. A healthy vegetarian diet... I'm not talking about the vegetarians who live on potato chips and orange soda

Vegan diet-
No meat, dairy, eggs, honey, animal products, etc. Basically your average vegan diet. I'm not really very familiar with vegan diets so I'm not sure what kind of animal products are allowed or not.

There is no right answer for this because everyone's dietary needs vary from person to person. In general a balanced diet varied in fruits vegetables, whole grains and protein sources is the healthiest and honestly these could apply to any of the diets you listed here.

vegan. you can eat as much as you want. its the healthiest too.

Vegan
You should eat as less meat, dairy producs, yeast products as possible, because they all effect your body pH balance (too acidic).