Which is the best round flat iron?

The best flat iron is the Karmin G3 Salon Pro, it heats up to 450f with temperature control, dual voltage, tourmaline ceramic plates with rounded edges which makes it great for also curling your hair. Also has a 3 year warranty.  You can buy from http://MyHairStylingTools.com or if you are in Canada you can buy at http://http://www.rylees.ca  . Or check out the reviews at http://flatironsreviews.com . It works pretty good with any type of hair.  I hope this helps.

The Chi

There are a few different curved flat irons out there.  Brighten Beauty Supply has a Hai Tong Digital Ceramic Curved Plate Flat Iron selling for $118.20.  Hai Tong Digital Ceramic Curved Plate Flat Iron with Thermal Travel Bag is ideal for creating circular, smooth shapes because of its unique 2W x 3 1/2L ceramic plates and crescent moon shape.  Sally Beauty Supply has the Jilbere de Paris Ceramic Tools curved flat iiron selling for $37.99.  ilbere Ceramic Tools Porcelain Series Professional Flat Irons feature porcelain plates. Porcelain is a fine ceramic compound with greater strength and durability for precise heat distribution and state-of-the-art performance. The "diamond hard" surface allows the hair to gently glide through the plates, preventing snagging and breakage. When introduced to heat, the porcelain ceramic emits far infrared heat waves, which have longer wavelengths. Heat at this level is more easily absorbed by the hair, resulting in enhanced vitality, reduced stress, and healthier hair.  Amazon has a Hot Tools Ceramic Titanium curved plate flat iron selling for $54.99.  Plates are coated in Ceramic + Titanium creating a Micro Shine surface.  Rounded plates and interchangeable fine and medium hair guides grip hair to create curl at the tip, avoid the "stick straight" look. Soft-Grip(tm) handle and variable heat settings