Character Concept: Cocky Duelist
Keywords: Rapier, Charming, Quick-on-his-feet 
This little thought-exercise has value, as I am playing a bard in a 4e campaign right now. However, though I like the way the bard plays, I am not a fan of the flavor, so here is another take on a roguish rogue. Without further ado:
Name: Raef – Human Rogue
1st Level Choices:
Class Feature: Artful Dodger
Background: Noble ( Diplomacy as a class skill)
Abilities:
STR – 10, CON – 11, DEX 17, INT – 14, WIS – 8, CHA – 16
Skills: Acrobatics, Athletics, Bluff, Diplomacy, Streetwise
Feats: Rapier Proficiency, Defensive Mobility
Powers: Clever Strike, Deft Strike, Sly Flourish, Fox’s Gambit, Trick Strike
We are well on are way to building an excellent duelist. His powers focus on movement and gaining combat advantage, and his feats grant him his rapier and the ability to worry less about moving across the battlefield. At level 1 he has a +5 bonus to AC against opportunity attacks. Skill wise, he diplomacy and he’s not afraid to use it.
2nd Level Choices:
Feat: Martial Alacrity
Power: Battle Feint
Both of these choices scream duelist to me. Martial Alacrity ups the initiative and essentially allows for an extra shift during the first round of every combat; battle feint highlights your skill with the blade and lets you spread the combat advantage love.
3rd Level Choices:
Power: Flamboyant Strike
A tough choice between this and Trickster’s Blade – however, I like the Errol Flynn version of a duelist so keep on movin’ when in doubt, and this one lets you shift.
4th Level Choices:
Stat Bump: Dex & Cha
Feat: Action Surge
Any duelist worth his salt relies on his grace and charm. Oh and the flair for the dramatic moment . . . hence Action Surge!
5th Level Choices:
Power: Flashy Riposte
An immediate reaction that sounds like a dueling move is a natural fit. Added bonus of dealing damage on the enemies turn and gaining combat advantage for a while makes it a solid daily.
6th Level Choices:
Feat: Improved Initiative
Power: Dodge Step
Dodge step keeps you away from your enemies and on your guard. Improved Initiative should be in the repertoire for anyone who relies on speed in combat.
7th Level Choices:
Power: Rogue’s Luck
A swashbuckler is never down and out . . . he is just setting up the next thrust of his sword. And that is why Rogue’s luck is a winner. It is a reset power. If you miss, go again. Perfect for frustrating the DM.
8th Level Choices:
Stat Bump: Dex & Cha
Feat: Skill Focus (Diplomacy)
Obviously, I’m not a min-maxer . . . you should have picked up on that by now. Hence, Skill Focus Diplomacy. By now you’ve probably saved a few lives, wooed a few women, and that needs to be shown in your Rico Suave charisma stats.
9th Level Choices:
Power: Vexing Escape
Ok, you hit someone then shift your Dex. Then when they get near you, you shift again. Then again, then again. That is just a top notch daily for a duelist. At this point you are likely the most aggravating character on the board simply for the amount of movement you get with your attacks.
10th Level Choices:
Feat: Weapon Expertise (Rapier)
Power: Combat Tumbleset
Well, it’s about time we invested some ranks into that rapier. Combat tumbleset is yet another power that lets you shift across the battlefield. By now you are a whirling mass of rapier stabs and smooth as butter charm.
NOTE – This character is not optimized. I know.