I assume that you are asking about the finnished product. Well, here goes.
My favorite is the old 1/72 Airfix Lockheed P-38F (early) Lightning. I think that this aircraft, with its small swept back engine nacelles, was one of the most beautiful fighter planes ever built.
After several hours of building, I thought that I had bitten off more than I could chew. This is what I had to do to make this bow-wow kit look like something (it was the only game in town):
Sand and remove all of the "boiler plate" rivet detail.
Scribe many new panel lines.
Scratch build a complete cockpit interior including some PE.
Vacuum form a new seat and canopies.
Open boom radiator outlets.
Separate elevator and correct the position of its mass balance.
Fill more seams than ever had to do, even to this day.
Make wheel covers.
Replace nose guns with steel tubing.
Added many other small details.
Amid lots of cursing and swearing, I hate to tell you how many times, this thing almost ended up against the wall.
Those were the times when the atmosphere around my model table was a bright purple! However, after all was said and done, it turned out to be a little gem. I was lucky enough to win two firsts and a second in model contests here on Long Island.
This taught me a valuable lesson. Never not build a kit because you think that it will be too difficult. If you like the subject, build it! With some extra time and attention to detail, anyone can build any kit. You just might surprise yourself![:0]
Pete