Originally posted by OregonJim I'll second Marc's advice - very well put.
You might consider the Tamron 90/2.5 for macro - it can also double as a portait lens and, with the matching 01F flat-field teleconverter, you get a 180mm telephoto for covering some wildlife work.
If you get the Tamron 90mm f/2.5 Macro (the old MF version, either 52B or 52BB
Tamron 90mm f/2.5 1:2 Macro #52B) you might also consider the 1:1 matched extension tube #18F in addition to / in place of the 01F 2x teleconverter. Also look for the #18FH optional hood.
You might also consider the Vivitar Series 1 105mm f/2.5 P/KA Macro - a complete, 1:1 Macro lens (an entirely different and higher price range) - very sharp and nice bokeh..
Both are available here and / or auction sites fairly often - the Tamron almost constantly available in conditions ranging from NIB to decent/used.
Either makes a serviceable portrait lens, but the Tamron does it better, as it was designed with that secondary use in mind. Amazingly sharp and the most stunning "SNAP" into focus of any lens I have ever owned.