Weakest class, What is the weakest character types in the game? Options

[Ryel ril Ers]

The topics a little bit strange, but i want to hear pros and contras of the "weak" classes.

One: The players see what are the worst choices, and which character better that position.
Two: There are nonliked classes and i want hear that they are really useless.

[trufa]

The Weakest single Class is the Monk, because he is the weakest in early game. Of course, he is brutal at the and, but which Class isn't.
The weakest multiclass is Thief-Cleric, because few spells, few ThS-s, for a Single class, but too much ThS-s, as needed.
The Weakest Dualcasses are the divine spell user, which a non spellcaster class have in second class, because too few spells.