Baldomir for me... Lovely guy but poor boxer... Ricky Hatton's reign as the 140lb lineal champ had a few duds on there but he did fight Mallignaggi and Pac who were, respectivly, the 2nd best in the division and the best P4P in the world at the time of the fight. However, defences against Maussa, Urango, a shot Castillo and Lazcano do weigh against him.
He only fought Maussa, Urango, Castillo, Lazcano, Mallignaggi and Pacquaio at 140lbs after beating Tszyu. Now, apart from the last two, how many of those make his record stand out as anything but average?
He lost to Pacquiao so shouldn't be included on that list. I could fight Wladimir Klitchsko for the lineal title and get sparked out in 30 seconds. Doesn't mean that I have a solid resume. So we're only really taking Tszyu and Mallignaggi into account... Hopefully your comment "Tell me the lineal champion`s that have better ledgers at their weight" doesn't apply to EVERYONE who has been a lineal champ because even Cory Spinks' wins over Mayorga and Judah at 147 are better than the two you've given us to work on. Out of the current lineal champions I would put Marquez's wins against Casamayor and Diaz on-par with those two.
Erdei gets my vote. You could definitely argue that a guy who loses the title in his first defence is worse but the way this painfully average fighter is holding the title hostage offends me.