There is an entire thread discussing best in slot gear for various specs. Search and read a little before posting.
There's something I've been wondering for awhile now that I can't answer for myself as of yet because my guild isn't currently at the level of doing what needs to be done to get a full set of the gear I'm talking about;
Which would up DPS more, or be more efficient: BiS gear with Armor Pen, or 4set Bonus of tier8 for the 20% increase per disease on Heart Strike?
With all of the Armor Pen on the BiS gear, and getting a full set of that rather than four pieces of tier gear, I can imagine that it would add up to a high amount of Armor Pen, seeing as I don't have too much Ulduar gear as of now but I have over 20% Armor Pen on my character page.
But is the 20% extra damage per disease, adding up to 60% with Frost Fever and Blood Plague, rather than 20% without the set bonus more worth it for DPS?