Garlic: raw for the antimicrobial properties and the cardio-protective nutrient allicin. If you chose to cook your garlic, cook it on low temp. The wonderful aroma of garlic cooking is actually the allicin blowing in the wind.
Tomatoes: cooked. They have more of the anti-cancer phytonutrient lycopene when cooked, especially potent when cooked with a little olive oil.
Zucchini: cooked. Squash delivers more beta carotene, a building block for vitamin A when cooked.
Bell peppers: Raw. Cooking will damage the b vitamins, so enjoy your peppers raw.