Okay, let's get going on the "who would win in a fight?" competition! For an explanation of the ground rules, check out this post.
The first match-up is between Sydney Bristow (ABC's Alias, 2001-06), played by Jennifer Garner, and Xena (syndicated, 1995-2001), played by Lucy Lawless. In case you are wondering, Garner is 5'8", while Lawless is just a shade under 5'10".
In Alias, Bristow is a UCLA graduate student who secretly works undercover for what she thinks is the CIA, going on aglobetrotting covert missions; except at the end of the pilot episode, she learns that she's actually been working for a terrorist organization known as SD-6. Bristow is quite skilled at armed and unarmed combat. Here's an example:
Xena, also known as Warrior Princess, was once a supreme baddie who slaughtered masses of innocents as an evil warlord. Unfortunately -- and I say this because she was always more interesting in the flashbacks as an evil character -- a run-in with goody-two-shoes Hercules caused her to seek redemption and try to atone for her past. Fortunately, she retained her fighting skills:
As appealing of a match-up as this might have seemed, I just don't see how Sydney Bristow would be able to last against Xena. While Bristow quite competently dispatched her foe in the clip (kicking his head through the car window was a nice touch), she seemed more convincing in the running scene than in the fighting scene. Xena, on the other hand, dominates multiple foes, and while most of those are dispatched by sword, under the ground rules of the competition (basically, the asteroid from the Star Trek episode "Arena"), I don't think she would have much trouble finding sword or staff-like weapons.
I think Xena would win pretty easily, probably within half a minute, and move on to face the winner of John Reese (Person of Interest) versus Captain Picard (Star Trek: The Next Generation).