in my opinion, this is the best PVE Sword spec for Maximum PVE DPS. This does not figure in poison immune bosses because I always found speccing for 1 or 2 boss fights to be stupid.
http://www.wowhead.com/?talent=f0eboyZMIVobVzxMGot
There are a few things to note about it:
Assassination talents:
You can go 5/5 leth or 5/5 vile, vile will do more total DPS until you reach a high gear level:
With S2 slicer, ~3000 AP raid buffed, 25% crit, 308 hit, lethality is adding about 3.06 DPS per point, vile adds 3 DPS to your DP ticks.
Combat:
Lightning reflexes can be exchanged with gouge, i prefer gouge myself.
Vitality: I chose this because it does increase damage by a very small amount, it can be moved anywhere else though. IMO, Imp kick is a must.