What will be the least best Protoss unit?

When this day comes, it'll be the day i make the biggest Cruiser fleet i've ever made and the same day i'll end up punching my comp screen, and the same day where I shoot like a billion Yamatos at one time at one single unit i will loathe until SC3

 

i hope the first time it happens to me is when the enemy does it on my ground =D
hey....can floating buildings get sucked in!?

 

I can't tell which one is the least useful right now but there are units with certain weaknesses

Phoenix - weak against ground
Immortal - low mobility
Mothership - only 1
Soul Hunter - the protoss's vulture......vultures were quite useless in SC1

I'll add to this list as more comes to mind