The tricky part about answering this is that there are a decent number of meaningful variables. I think the 2 biggest are the attack set pairing and whether you include incarnate. Alpha and Destiny can close holes in pretty much any set. Dark melee can take care of healing and still be very effective. MA can top off defense for the resist sets. I don't think it's realistic to look at sets "in a vacuum", because that's not how they are played in the game. Likewise, no skimping on IOs, doing so is another unnecessary variable in the current game.
That said, I want a set that does it all. Soft-capped defense, high as possible resist, decent healing, and debuff resistance. The sets that I feel comfortable playing at an uber level are Stone, Bio, Rad, and Shield. Invuln and Electric might be in here, but they just feel a notch lower to me. Invuln might be nerf bat prejudice, but all of the above add something offensive and can get virtually the same defense.
Stone, Bio, and Shield are silly easy to make awesome. Shield doesn't have the resists, but its DDR is the best. The click debuff resist is meaninglessly easy, since it lasts 2 minutes and is up in half that. Double stacking it also makes the DDR uber, which is important. Arguably the most offensive of the 3.
Bio is nice because switching to Defensive is what the Tier 9s should be for every set. You can be uber in Offensive mode, then sacrifice a little offense to save your butt in emergencies.
Radiation might need MA to be uber, but it is really top tier with it. Soft-capped defense except for AOE (and then only Cold, Toxic, or Psi). Capped resists in everything except Cold, Psi and Negative (close). Solid regen, plus Rad Therapy. High end AOE damage and ST. 2 good AOE to cover MA's hole. Just let me turn off those damn f/x...
Tanks do enough damage (and everyone else is so tough) that Taunt is an unnecessary loss of dps. If you have decent AOE damage, you're already aggroing everything you need to aggro. Most teams don't stay on one spawn anyway, and all the aggro mgmt in the world doesn't matter when they hit another group 60' away. Some might frown on it but those who know, know.