Over the years I have experimented with several different diets ranging from the S.A.D (Standard American diet to Raw Vegan). Below is a comparison of each diet, how difficult they are to maintain and what each diet generally consists of.

Standard American Diet
Difficulty: 0
Why: Very flexible, most people eat the same thing
Feeling: Normal (after a while), Sluggish (after being on a healthy diet)
Staple Foods: Whatever you want
Precaution: Dietary deficiencies, More likely to lead to health issues in later life
Willpower Requirement: Dependent on desired health level

Vegeterian
Difficulty: 2
Why: Relatively easy, can be a little bit difficult in social settings
Feeling: Healthier, more likely to get tired
Staples: Fish, Chicken, Vegetables, Fruits, Grains
Abstain: Meat, Animal Products
Precaution: Dietary deficiencies, Heightened risk of Anaemia
Required to make it work: Supplements, research, a varied diet
Willpower Requirement: 3

Vegan
Difficulty: 3
Why: Difficult to eat out or with family/friends/colleagues
Feeling: Healthier, more likely to get tired
Staples Foods: Vegetables, Fruits, Grains
Abstain: Meat, Poultry, Animal/Dairy Products
Precaution: Dietary deficiencies, Heightened risk of Anaemia
Required to make it work: Supplements, research, a varied diet
Willpower Requirement: 5

Raw Vegan

Difficulty: 5
Why: Difficult to eat out or with family/friends/colleagues
Feeling: Alive, energised, more likely to get hungry
Staple Foods: Raw food, Dates, Salads, Dehydrated foods
Abstain: Cooked foods, Meat, Animal/Dairy Products
Precaution: Dietary deficiencies, Can cause extreme weight loss
Required to make it work: Supplements, research, a varied diet
Willpower Requirement: 5

Note: For best health, organic foods are recommended for Vegan and Raw Vegan diets.