I consider this to be the first "good" image I ever captured.  I took this picture of the Mannheim water tower (Wasserturm) while I was living in Germany in 2010.  This picture is still included in my portfolio.

I had just purchased my first DSLR (the 12 megapixel Canon 450D) and was still learning the basics of photography.  Using the kit lens (my only lens at the time), I would walk around the city playing with different settings and techniques.  The Wasserturm was my favorite place to experiment since it was only a few blocks from my apartment.  I visited the Wassurturm almost daily.

I didn't have a tripod, so I took several images back-to-back and hope one was sharp; the chance is greatly improved with Image Stabilization.  This was shot as a JPEG since I didn't yet understand the advantages of shooting RAW, nor could I justify the additional storage space required.

If I were to re-take this image today, it would be shot with a 51 megapixel Canon 5DS using a tripod.  It would be perfectly sharp and perfectly exposed.  There would be less noise, less distortion, and more dynamic range.  And yet, at the size above, I don't think anyone could tell the difference.  Expensive gear and flawless technique can't replace creativity, eagerness to explore, or the perseverance to get that perfect shot.