Listing traits to be removed is incredibly boring, but what exactly could be enhanced on a human body without facing ethical issues? After all, of all the animals that I know of, human being is one of the less genetically capable one.
 
Let our imagination run on the subject for a while.
 
Body and mind improvement are for sure interesting, but maybe not possible. It could be thought that our muscles and brains can be optimised for better performance through genetic engineering but I doubt much improvement can be done. Evolution has been working at it for already 4 million years. Plus: the genetic implications are so intricate that this kind of modification is nowhere near in the future.
 
Night vision, on another hand, could probably easily be fitted to human eyes. Tapetum lucidum, that equip already some nocturnal animals, making their eyes shine when a source of light is directed into them, could be implemented in human eyes without major difficulties. Some primates (that is the sub-genre of human specie) have it. It has no drawbacks so far. I don't suppose that anyone is happy with the inability to see clearly in the dark.
 
Thermal regulation could be improved to better adapt the variation of temperature. The human body increases a little bit the metabolism when the temperature drops, but still requires the addition of garments to withstand anything colder than, say 15°C. That is the average temperature of the globe! I don't think it would be a big deal to allow the organism to burn more calories in case of cold temperature in order to achieve the metabolic temperature.
Though it might prove to be a devolution in case the human race was to return to a jungle life. This point is debatable.
 
Sexual drive: Evolution has fitted us with a sexual drive ensuring that the individuals of human specie strive to propagate their genes. Though this sexual drive probably proved to be very useful in a past where the humans were not many and subjected to their environment, in today's situation it is by far higher than necessary. Plus: it is entailing very antisocial behaviour. The psychological consequences of hormone manipulation is indeed very intricate, but anything can be solved, given the means and the energy. And the benefits on the social level are far greater than that of any previous man-made artifacts.
 
I'm still extending this list. So far I came up with:
 

• A reversible slowing of the growth of hair and nails.
• Underwater breathing.

• Pockets! Yeah, like kangaroos, but on the sides.
• Getting rid of sleeping
• Getting rid of old age (old age is a genetic time-bomb).

If you have an idea, put it down in a comment, I'll add it with credits to you (I have to... for the CC licence).