Here's a basic way to do it, with a few thoughts on varying it based on class levels, or if you want to fight with two weapons. I'm using the elite array, the PHB, the DMG and Complete Warrior, btw (since those are what happen to be on my desk at the moment). I'm also presenting a bit more of a swashbucklery view than a pure power build - obviously, swap Charisma and Constitution if its more of a dungeon crawl.
10th level Human Fighter
Str: 14 (13, +1 at level 8)
Dex: 16 (15, +1 at level 4) [18 with Gloves of Dexterity +2]
Con: 8
Int: 14
Wis: 10
Cha: 12
Level 1: Weapon Finesse
Fighter 1: Weapon Focus (Rapier)
Human Bonus Feat: Combat Expertise
Fighter 2: Improved Disarm
Level 3: Improved Toughness (Complete Warrior)
Fighter 4: Weapon Specialization (Rapier)
Level 6: Dodge
Fighter 6: Mobility
Fighter 8: Improved Critical (Rapier)
Level 9: Iron Will
Fighter 10: Combat Reflexes
Equipment (49,000 gp): +1 Light Fortification Mithral Shirt, +1 Wounding Rapier, Ring of Protection +1, Amulet of Natural Armor +2, Gloves of Dexterity +2, Boots of Striding and Springing, Cloak of Resistance +2, +1 Mithral Shield, 60 gold.
AC: 25 (10 + 4 Dexterity + 5 Armor + 3 Shield + 2 Natural Armor + 1 Deflection)
HP: 50.5 on average
Saves: Fort +8, Ref +9, Will +7
Full Attack: +16/+11 (1d6+5/15-20, +1 wounding rapier)
Skills: As a human, you would get 5 skill points per level. I'd probably recommend a steady diet of movement-based skills; Jump, Climb, Tumble, Swim, etc. If you want to play up the Swashbuckler aspect (and especially if you take levels of Swashbuckler or Rogue), Bluff, Intimidate, and Diplomacy are good as well. Obviously, take a level of rogue or swashbuckler at level one, if you take any at all, to increase your skill points.
Overall, you could be a lot more powerful; you'll be hit a decent number of times, and you don't have the best hit points. You also do fairly mediocre damage. Some of the things below could help with the AC and the damage output, and may be worth looking into.
Variants:
-Swashbuckler levels will add a few more skills, a small bonus to your Reflex saves, the ability to add your Intelligence bonus to your damage, and Weapon Finesse for free, among other things.
-Rogue levels will greatly increase your skill points. You also gain sneak attack (to help ramp up your damage), evasion, and uncanny dodge (as well as improved evasion and improved uncanny dodge, if you stay in the class long enough). Due to the loss of hit points from Rogue levels, you'll probably want a 14 Constitution, a 12 Intelligence, and an 8 Charisma if you take more than one or two levels of Rogue.
-Duelist levels allow you to add your intelligence bonus to your AC and greatly increases your Reflex saves. Eventually, you'll get Precise Strike, which lets you do an extra 1d6 (2d6 at level 10) damage. You'll want a minimum of one level of swashbuckler or rogue, so that you can get the requisite ranks in Tumble quickly; the ranks in Perform are easier.
-Dervish requires Weapon Focus in a slashing weapon, so you may want to switch over to the scimitar (which becomes a light weapon for a dervish), and makes you really, really mobile. Switch all instances of Rapier above to Scimitar, pick up three ranks of Perform (dance), and you're ready to go.
-Two-Weapon Fighter. Not specific to any class, obviously, but you'll want to be mainly a fighter to get as many feats as possible (if you could justify it, two levels of Ranger wouldn't hurt at all). You'll obviously need Two-Weapon Fighting. If you want Improved Two-Weapon Fighting, you'll need a 17 dexterity (or 6 levels of Ranger, which will greatly limit your feats, and may call for a higher Wisdom so you can use your spells). Weapon Focus in an off-hand weapon (or switching over to short swords) is a possibility, as is Two-Weapon Defense. Consider going to a longsword, scimitar or short sword for the main weapon (or convincing your DM to allow your rapier to count), and a dagger in the off-hand; if you pick up weapon focus in both, and Improved Two-Weapon Fighting, you'll qualify for the Crescent Moon Style from Complete Warrior, which makes you a lean, mean disarming machine. Either drop one of the magical items from the equipment, or reduce the rapier to a +1 Flaming (or whatever damage type you like) weapon to free up cash for a magical off-hand weapon.
