There's a human fighter 20 npc who's all about the greatsword in my campaign, here's a quick copy-and-paste of his feats:
Alertness, Cleave, Combat Reflexes, Great Cleave, Guard Your Flanks, Improved Critical (greatsword), Improved Initiative, Iron Will, Lethality (greatsword), Lightning Reflexes, Point Blank Shot, Power Attack, Quickdraw, Quick-Strike, Weapon Focus (greatsword), Weapon Mastery (greatsword)
A few of those are obviously custom feats, so I'll copy & paste them in as well:
GUARD YOUR FLANKS (General, Fighter)
Your combat training has led to a high awareness of enemy flanking techniques and a good defense against them.
Prerequisites: Base attack +6, Combat Reflexes, Lightning Reflexes
Benefit: Whenever an opponent moves into flanking around you, you immediately gain an attack of opportunity against that opponent.
LETHALITY (Fighter)
You are extraordinarily lethal with your chosen weapon and are adept at slaying your foes in a single blow.
Prerequisites: 12th-level fighter, Improved Critical, Weapon Focus, Weapon Specialization
Benefit: Whey you roll a natural 20 on a roll to confirm a threat your opponent must make a Fort save against the damage you deal or die instantly. (You cannot kill a creature unless you are inflicting real damage.)
QUICK-STRIKE (General, Fighter)
You know how to initiate battle with astonishing speed.
Prerequisites: Improved Initiative, Quickdraw
Benefit: In the first round of combat in which you can act, your initiative is treated just as if you had rolled a 20. Roll normally the second round.
WEAPON MASTERY (Fighter)
You are a master of a specific weapon.
Prerequisites: 10th-level fighter, Weapon Focus, Weapon Specialization
Benefit: Choose one weapon you already have specialization in. Before each attack roll with you mastered weapon you may allocate a total of +2 to attack and damage rolls. For example, you could declare a +2 to attack, a +2 damage bonus, or a +1 on each. You may change your mastery bonus around with each attack roll. Unlike specialization, a damage bonus from mastery applies even past 30’ with a ranged weapon.
I hope at least the list will be helpful, even if you don't like the specific feats. You'll note that a couple of those require lots of fighter levels as prereqs; that's because I think high-level fighters should have access to something nobody else does, and feats are their mechanism for getting spiffy abilities.