I think Dreadknight beats samurai, but I think samurai is pretty close to as good as it. Dragoon I think is the lowest, and I think Paladin is in the middle, probably the closest to balanced atm.
I can beat a dreadknight as a samurai, but it matters who the dreadknight is. If you know how to use your skills as a DK, you can beat anybody, except maybe a necro...
I've been debating on whether or not I want to go back to DK, because all-in-all, it's my best class. But I really enjoy the ability to use a sword as a samurai, and I like having the ability to demolish wizards after their devastating combo. Honestly, if I were to go back to DK, not much would change, except for me having to switch back to an axe, which I honestly am not fond of. DK +Potions = insanity
EDIT: I wanted to add, that I have never lost to a dragoon.... I think that an average samurai can easily beat an average dragoon... so i think samurai should be up there next to DK.