I’m going against Salamis. 2 points.
Ditto: Salamis, two points. Gotta give Nelson his due.
Both worthy choices, but again, I can’t believe a unanimous decision should be in the offing.
Trafalgar – 2
De-lurking in support of the Greeks.
Trafalgar, 2.
Voting for Trafalgar - 2.
2 for Trafalgar.
Salamis - Decisive tactical and strategic victory that assured naval dominance throughout the rest of the war, but did not end the war or assure its success. Nonetheless a key moment on the road to eventual victory.
Trafalgar - Even more decisive tactical victory, less decisive short-term strategic victory. Like Salamis it also assured naval superiority, but while the Greeks would go on to win their war, the anti-French alliance would soon lose to Napoleon on the ground at Austerlitz. Often marked as the rise of the total British naval dominance, but that really isn’t quite the case IMO. More importantly I think a British defeat probably would have been of less immediate consequence than a Greek loss.
I think Salamis has to bulk a bit larger between the two. Also Trafalgar is tainted by the unmanly use of gunpowder ;).
Trafalgar - 2.
Wow this is tough. Trafalgar featured a higher percentage of damage to the defeated side, and a better ratio for the winners, but substantially fewer ships – Salamis was epic in scale.
IIRC Themistocles placed pretty high in the Greatest Military Leader thread, too.
Nelson faced a more vexing tactical problem, though, in bringing the ponderous sailing vessels into a position to force a deicsion – Themistocles’ problem was essentially the same one every badly outnumbered force faces.
After much agonizing, I’m going to go against Trafalgar, despite my personal admiration for Nelson’s achievements and the fact that I’d much rather be a Jack Tar on HMS Victory than a sweating Athenian oarsman.
Trafalgar - 2
I am also going against traf,
Trafalgar - 2
New thread opening - get yur behinds in there especially Tamerlane 
:
http://boards.straightdope.com/sdmb/showthread.php?t=607184&page=2
Salamis is the winner!
Damn you, Greeks!
Horatio will have to comfort himself with Emma. 
Ah, well. I thought I could see it coming.
And Emma was hawt, so I don’t feel too bad.