That's a decision that only you can make, but we can help! If you want a super light frame, go with one that's 15 grams or lower. Titanium frames are generally very light. If you want a durable frame, go with stainless steel or memory titanium. If you are allergic to metals, stay away from metal alloy and memory titanium frames, both of which use nickel, an allergen. Stick with frames made of hypoallergenic materials, such as stainless steel or titanium. If you like plastic frames, choose an acetate frame, because acetate is cellulose-based, and therefore hypoallergenic.