If not Aperture, then what are you using on your Mac?

Lightroom for 90% of my photo management, editing and storage.  Photoshop CS5 for detailed editing that Lightroom can't handle (such as panorama stitching, HDR and content aware fill).  Canon Digital Photo Professional for subtleties (such as identifying focusing point) that Lightroom does not display. Silkypix 5 for my Panasonic FZ200 when I want to do quick and dirty RAW conversions.  If I had to pick one, it would be Lightroom, no doubt about it.