Russian Red is a firm favourite of mine, and definitely the perfect red for me. Its blue undertones mean it doesn't make teeth look too yellow, and it's described by MAC as an "intense bluish red".
This is a must for Autumn when you don't fancy an obvious berry-toned choice. I wear it with a red Rimmel liner underneath to increase its longevity. It has a matte finish, so lip balm before and after wear is essential.