If your budget is tight, then I'd say that a combination of the 50mm 1.8 and 85mm 1.8 is a no-brainer. Some can get a little elitist about the cheap build of the 50mm 1.8, and whilst the focus not the fastest around, for the money I'd say that only a fool would pass it up and not have a 50 in their bag. The 85mm 1.8 is just a beauty though, and whilst it might get a bit tight on a crop sensor, the image quality of it is pretty much second to none at the price it is at.