As a great warrior, I wouldn't limit myself to one weapon as that is likely a death wish with everything everyone has said so my weapons are as follows.
- Nodachi with a sheath that allows for easy drawing as I don't want to take a minute to get the sword into a defensive position
- Set of six badass throwing knifes
- Two H&K USP Tactical .45
- A Gauss rifle
I'd also get extensive genetic modifications done so not only can I carry all that and the ammo for the guns, I could also survive falls from 25,000 feet and preform short range, near-instantaneous travel.