Best Ammo Power?

This one might be easier, and it's another poll.

I opted for picking 2 answers, because half the classes get at least 2 ammo powers to start, and any class can pick one of the bonus ammo powers (assuming unlocked)



I vote for Incendiary and Warp ammo.
Incendiary because Vanguard, and Warp because Sentinel.

In ME2 Incendiary ammo makes your SMG and shotgun into multi-purpose weapons that gets a bonus against everything, making the Vanguard a jack-of-all-trades in it's own right.
Warp ammo gives the Sentinel a great boost to damage and synergy.

In ME3 Incendiary ammo can get Explosive Burst, turning every gun you use into a micro-grenade launcher.
Warp Ammo synergizes so incredibly well with Warp that the Sentinel can basically just use Warp (power) then shoot, even on shielded enemies.

I'll give an honorable mention to Cryo and Disruptor as well.
Cryo ammo for a Vanguard gives you the perfect ammo to squad-out for your team, whether ME2 or ME3.
Disruptor ammo I'll concede is a solid choice whether focused for yourself or squadded-out.
Armor-Piercing ammo IS good, but I find the mods that allow for piercing work better, and if you want the weakening effect, then Warp ammo is better.

My opinion on the "best" ammo power per class:
Soldier: Disruptor
Adept: Warp
Engineer: Armor-Piercing
Infiltrator: Cryo
Vanguard: Incendiary
Sentinel: Warp

The Engineer is the only class I see getting the "best deal" with Armor-Piercing ammo because it frees up a mod slot for an Extended Barrel or Power Boost, and an Engineer benefits more from power-spam than weapon damage, so Armor-Piercing lets you focus on Overload while your gun(s) hits the armor.
If you want to be a tech class that uses weapons in a more primary capacity, then you would pick Infiltrator, which already has ammo powers, or Sentinel, which arguably doesn't need them in the first place but can get a lot of mileage out of one.