Biomods, any day, every day
First of all, I'm assuming it has gone as far as possible in terms of research, so that any biological augmentation, either in an animal/plant/bacteria/etc is applicable to humans, as well as certain homebrew mods that are within the realm of reason.
First off, give me a few more amino acid generators and nutrient producers, and a chloroplast and whatever is in a chemoautotroph, so I can survive with just sunlight and water, or just chemicals, or the standard human method of eating. Give me a more efficient method of cellular respiration where it recycles Oxygen or converts other chems to Oxygen so I can live anywhere with an atmosphere, and not need to breath for hours at a time. Give me cell regeneration for near immortality, and extend my cells life so the can reproduce as many times as they damn well please. Induce many periods of quick acting puberty, or perhaps integrate some DNA from a very large animal, so I gain several tons in muscle mass, and several meters in height. Expand my brain size 10 or 20 fold, reintroduce a baby's ability to retain infinite information that reforms the brain and specializes it to specific tasks that I undergo every day of my life. Give me the near bulletproof hides of many animals, the razor sharp teeth of a shark, a reinforced bone structure from a large elephant, altered slightly so I retain my ability to stand on my back legs, and a monkeys tail. Give me a trees ability to continue growing for 4000 years, and remove the ill effects of aging. Allow me the jumping ability of the jackrabbit, or perhaps the flea, the rapid movements of a panther or hummingbird, and the sprinting abilities of an ostrich or cheetah. Give me the nose of the bloodhound, the eyes of the owl, the inner ears of a rabbit, a dolphins echolocation, a fish's ability to detect electric fields.
So yes, I do prefer the biological modifications...
(I realize 1 or 2 of those things are slightly beyond the realms of reality, at least in our lifetimes, but a man can dream, can't he?)