Actually, it's better to consult a doctor first and have a blood test, self-treatment may be harmful. Only if there is a vitamin deficiency, it's necessary to take vitamins. Personally, I take vitamin D, C, B12, Omega 3, and zinc. Also, it's important to buy quality vitamins only, I buy all the meds at Canadian Pharmacy.
I generally like the Garden of Life brand, though I take individual vitamins rather then 1 multivitamin. It's important to know what you are deficient in before deciding on your vitamin options.