Yeah especially when you throw out all the Russians. Which we all should.
You got Carl Lewis in the arguement. Gold in multiple events 12 years apart.
Arguably tougher to run fast for 12 years than it is to swim.
Arguably Carl had to sit out a couple races that he could have won because of condensed track and field schedule.
Phelps did a bong hit.
Lewis butchered the National Anthem.
I think Lewis being the fastest runner for 12 years is a little more impressive. A little more unlikely, but nowhere near the medal count of Phelps.
Phelps is a way cooler guy too. Better sense of humor and a little more humble.