Personally, i'd go with the 520D to have both DVI and VGA at my disposal. On paper the specs are nearly identical but 520D owners are reporting a higher quality picture via the DVI input.
Otherwise they both seem to be nice monitors. I'm personally using a benQ 591 but i still have an unstripped 522A and the picture on it is excellent imho.
People also seem to like the 529A even more than the 522A.
3 decent choices but i'd personally go with the 520D for the reasons stated above. Remember to be a little more careful this time

, especially with ESD (static), which can kill components outright, or torture it with a slow death