Most circle lenses are designed to enhance your eyes, making them look bigger and more vibrant in color. I have tried many different circle lenses, but here is my absolute favorite pair, namely the Vassen Cloud Nine Blue lenses.

(photo from pinkyparadise.com)
The Vassen Cloud Nine Series is a series of very vibrant lenses that enlarge your eyes as well.
Diameter: 14.5mm
Water Content: 42%
Base Curve: 8.6mm
Type: 1 Year Disposal
I absolutely love these lenses. I have always wanted a pair of bright blue lenses that did not look too unnatural or made my eyes look alien-like.
These lenses look quite natural on me IF I'm wearing makeup. They do not look natural if I am not wearing any eye makeup, as they then look a bit weird.
Comfort wise, they are extremely comfortable. I have had problems with circle lenses before, but not with these. I cannot even feel them in my eyes when I am wearing them. However, I do need to keep eyedrops with me just in case my eyes get tired.
I got mine from PinkyParadise, and if you click the link it will take you directly to the lens page. I get all my circle lenses from pinkyparadise, as they are an amazing company with the most options of lenses. The shipping usually takes about a week from Malaysia to Norway, and that is with the cheapest shipping alternative. You always get a free animal lens case when you order ;)