I could have chosen Cleric, because they don't do "priest" particularly well and are, essentially, unaffected by their choice of god (oh noes! one variant spell/day). They're passible, though, so long as you're in a video game mentality.
I could have said Ranger because, well, it just isn't a Ranger. TWF still makes no sense. And I fail to see how a Ranger could have fewer hit dice than a Fighter. Ranger would take the #2 spot on my "Suck-o-meter".
I could have said Sorcerer because, while mechanically passible in the spells department, they are over all somewhat weak (fixed by a boost in HD or skill points). Flavor-wise, they are lacking and would be better done with an expanded Warlock. Also, each dragon-blooded feat or PrC makes me weep for the ignoble Sorcerer.
I could have said Monk because they always make me wonder: WTF? They have no flavor relation to the other core classes. And, they don't always do what they are supposed to do (kick ass with their bare hands) particularly well.
Ultimately, though, I went with Paladin. Why? It isn't the Pokemount (though that does suck). It's the fact that the Paladin is a near-perfect example of a Prestige Class concept. It should be in the DMG, just up the road from the Swashbuckler.