More brain cells, please
The brain, specifically one that is more adept to modern life.
- Extra index finger. We can type faster, play music better, and our number system would be based on 12.
- Better ankles. Humans are the best long distance runners in the world, but our ankles are built like wrists and get damaged easy.
- Maybe UV vision? You can see energy leaking out of power lines and stuff.
The more sweets it eats, the healthier it gets.
Something that enhances regeneration.