I use Aperture always as my first tool to work on the raw image. IMHO always go with a non destructive editing tool such as Aperture or Lightroom first, then move onto Photoshop later when you already have the basic adjustments done, it's just an easier workflow. Filters I use in Aperture are Fisheye-Hemi to reduce the barrel distortion of my 10.5mm lens and Noise Ninja for pictures taken at higher ISO settings.
I move onto Photoshop only when I need to use a filter that I don't have in Aperture. A professional photographer told me that dodge&burn in Photoshop are superior to Aperture but I am not experienced enough to comment on this. I like Photoshop for the wand tool, cutting things out and blurring backgrounds, however I only use it on 25% of the pictures I take, the rest is happy with a crop, exposure adjust, levels, colors and straighten in Aperture.
Have no experience with lightroom. Honestly, if you find something you like and find easy to work with: don't change or ask if there is something better 
If it works for you, it works!
Cheers,
Simon