I don't mean to sound rude, but if you don't even know what kind of photography you want to do so you are asking strangers on the net what class of lens you should get, then I say you aren't really ready for a new lens. If you can only afford one lens right now, pick the type you'll use the most. In which case it may be a macro lens.
You'll get most use out of a lens if you have a need for that type of lens. Getting a Macro lens for a person that likes to do wide landscapes will not be helpful and vice versa.
All the lenses you are considering are very good lenses and will perform well... If used for intended purpose. Having said that, I'd say go for the Tamron 17-50 awith maybe an extension tube. As it's a general purpose use lens and you will probably get the most use with it. The other lenses are more specialized and unless you like to do a lot of landscap/macro/portraits or whatnot, you won't get much use out of the lens.
Good luck
"YES! I AM INVINSIBLE!"-Boris
