[Bozos of Bones]

I myself find the rogue superior to paladin. His backstab is one of my favorite abilities in the game, and the after effects like Hamstring and Arterial Strike are superb. Envenom Weapon is very useful too. The paladin has Intimidation and Concentration, whereas the rogue has Intimidate, Bluff, Diplomacy, Use Magic Device, Disable Device, Hide... I can see a situation:
Paladin walks slowly through the dark corridor, his holy weapon ready in his right, the tower shield in the other hand. "Come out, face me like a man!"
Behind him, a flash of metal, a sound of flesh being cut and footsteps moving away. The Paladin turns around only to be stopped by the pain in his leg. He tries to walk, but finds it too hard to do so at any decent speed. He decides to lean against a wall, to avoid any further attacks at his back. He is loosing blood, he realises. After curing himself of the immediate wounds, he tries to continue his search of this thieving fiend.
Now at this point, the paladin has lost 1d6 Constitution and 1 Strength, is bleeding and is moving at half speed. His damage is negated by his Lay on Hands, but he is still at a penalty of combat effectiveness. The rogue is yet unharmed, hidden, and unless the paladin casts See Invisibility, will continue to use the tactics against him. If we have a 450hp Paladin, originally, and a 240hp Rogue, after the Paladin loses from 30-90 maximum health, starts bleeding and uses up his Lay on Hands he starts searching for the rogue. Even if he doesn't get stabbed again, the Rogue's AC with the Brilliant Shortsword +5 and Expertise are high enough to avoud being hit by the Paladin atleast every third attack or so, he hits the Paladin every time, as the Paladin's Dodge and Dexterity bonuses will most likely amount to 15 AC, but not more. If the rogue hits for 15 damage with every hit, and the paladin hits for 40 with every hit(let's say the Rogue is Chaotic Evil), the Rogue still deals more damage within a round if the paladin hits only 2 out of 4 strikes. And by adding Use Magic Device into the mix, the Rogue's options quintiple. After a few Lower Resistance scrolls(if the Paladin has 57 Spell Resistance), the guy can basically toy with the pally with spells. Sure, the paladin has some wildly impressive saves, but some spells don't allow them. Summons, for instance. Since the Rogue is no Spellcaster, he gets no penalties from Tenser's Transformation, making him as good a fighter as the Paladin.
In a no-holds-barred fight, the only melee characters I can see beating a Rogue everytime they fight are Barbarians and Monks. Both have speed, the Monk has a superhigh natural AC, and the Barbarian has Rage.
...
Damn, I should have made this a Poll.
So, my vote goes out to Rogue. Monks close second.