Paladin is the weakest
If you think rogues are weak, consider that depending on the campaign,
mounted combat might not be around much, so the bonded mount is either
very powerful (ride-by attack, spirited charge) or you never get to make
a charge.
Paladins are versatile, like rangers, but still only get 2 skill points a level.
Now, if you're fighting foes vulnerable to Smites, things start looking
better, but:
Consider being barbarian2/fighter8 w/ extra rage feat, so you can rage
3 battles a day.
Paladins are very attractive from an RP standpoint, but they have no
ability choices, just like 3e monks.
At minimum, a paladin is another plate armor guy w/ power attack, but has
too many stat demands compared to the fighter or bbn/fighter.
He does fill that plate armor w/ lots of HP role well though, and I have seen
one person build a paladin w/ 8 wisdom, cranking strength and doing
everything he could to be a melee monster.
Bards may not be powerful, but their versatility, like a ranger's, puts the
paladin to shame.
Paladin could easily have 4 skill points/level and not be overpowered.
I feel the guy who said rogues, but you have to think of them as versatile
first, and strongly consider the spring attack feat chain so that as a rogue,
you do not have to sit there and take the monster's full attack routine if it's
too dangerous.
The 11 classes can be divided into Power and Versatility camps:
Power
------
Fighter
Barbarian
Wizard
Cleric
Druid
Sorceror
Versatility
---------
Bard
Monk
Paladin
Ranger
Rogue
Fighter feats work vs. everything. Barbarian Rage works vs. everything.
Paladin smite doesn't work vs. non-evil (animals, aberrations, oozes, etc).
Ranger favored enemy doesn't work vs. others.
Wiz, Clr, Drd, Sorc can all lay down the smack or change an entire battle
from total party death to victory with one spell. Bard can sometimes do that,
but not reliably.
Monk and Rogue require thought, because they are the most versatile and
least powerful, especially at high level. They look nice at low level getting
2 flurries a round or an extra 1d6 on their weapon damage, nearly doubling
their output, but eventually the greatsword power attacking tanks outdo
them, and the spellcasters outdo even the tanks pretty often.
High-strength monks make expert grapplers and can rule all medium-sized
foes, even some large ones especially w/ an enlarge person buff.
Any monk with max tumble can tumble at full speed, through opponents, to
reach the wizard at the back and put him into a grapple he cannot escape.
He needs the party to keep the enemy off his back, but now the enemy
wizard is neutralized.
Using a "wimpy versatile character" like the monk to take out the enemy's
best spellcaster is HUGE. Of course, not all enemies have a caster in the
party...
The rogue is an excellent scout and tumble-attacker. The rogue's best
chances come when they win init and sneak attack a flat-footed foe, using
their bow (within 30') or when they let the fighters wade in first, and
then maneuver to flank the nearest wounded foe. (or, with enough movement,
spring attack into a sneak attack position, whack the foe and return back
where they started. a single level of barbarian for an otherwise pure rogue
is +10' movement and a rage... max UMD is eventually other ways to get
fast movement too. If the party wizard just hasted you, you have move 60,
and should be able to spring & sneak attack even huge creatures)
Rogue the weakest? Well, in set-piece battles, possibly. I've played in a
living greyhawk adventure that was all constructs, another was all undead,
etc. On the other hand, I've played in adventures with all monstrous
humanoids, and just cleaned their clocks. My rogue 6/fighter1, using
dwarven waraxe and buckler, got in a hastened full attack (two attacks total
at my best BAB) for two rounds vs. a stone giant. missed both times the
first round, hit twice the 2nd round, for 24 and 17 damage. We rogues love
that Haste spell...
every character build has their weaknesses, it's just that some (like rogue)
come up too often when the adventure authors get too enamored of
undead, constructs, etc.