A lot of people like the Tamron 90mm. I have a freind who gets great macro shots with it. There isn't really a bad macro lens currently in production. Something in the 85-105mm range would be a good all purpose macro lens. There are plenty of used lenses on the market. How much do you want to spend?
I do suggest avoiding 3rd party zooms that have "Macro" in the title. They really don't have the magnification of a macro, they just focus closer than normal zooms.