To be honest, Hale for me. Femshep just overall has that quality to it, she actually sounds like a Person. With Meer i always have this image of him just reading his Lines. But to be fair, Meer has improved, i mean compare Maleshep between ME1 and ME2, its a big Improvement. But still as said, to me Hale managed to make Femshep more a Character than just giving the Voice.
So in the end, they are both good, both got Ups and downs, Hale makes some paragon Dialogue sound a little flat as well, but i play Renegade anyway, though i do pick some Paragon Choices now and then, so they both work. Some of Hale's Renegade Dialogue is pretty epic, just as Meer's. Like the Renegade Option when Tali and Legion are bickering in ME2..thats just badass ;P