I had always used Braeburns, but Serious Eats says that properly treated GOLDEN DELICIOUS -- an apple I had always assumed was a genetic mistake -- actually make the best pies.

It takes golden delicious to make the pie super delicious?! Okay, I'm sold.

Wikipedia factoid:

In 2010, an Italian-led consortium announced they had decoded the complete genome of the Golden delicious apple.[7] It had the highest number of genes (57,000) of any plant genome studied to date.

https://en.m.wikipedia.org/wiki/Golden_Delicious

So is that the most genes you can eat in a fruit?

While checking (because tomatoes!) I found a - if not the - most fascinating link:

There is a staggering diversity of genome sizes. The smallest genome (3) so far reported (0.0023 pg of DNA) is found in a parasite (Encephalitozoon intestinalis) of humans and other mammals. The human genome, at 3.0 pg, is 1300 times larger than this, but this pales into insignificance compared to those found in some animals and plants.

Among animals, some amphibians have enormous genomes, but the largest recorded so far is that of the marbled lung fish (Protopterus aethiopicus) with 132.83 pg(3) . Among plants, the record holder for 34 years was a species of fritillary(4) (Fritillaria assyriaca) until earlier this year when a Dutch group knocked the fritillary off the top spot when they found that a natural hybrid of trillium (Trillium × hagae), related to herb paris had a genome just 4% larger than the fritillary (132.50 pg).

This was widely thought to be approaching the maximum size that a genome could reach, until this summer when a team of Kew scientists discovered that the genome of another close relative of herb paris, Paris japonica from Japan, is a staggering 15% bigger than the genome of either the trillium or the fish at a whopping 152.23 pg

Ilia Leitch, Research Scientist in the Jodrell Laboratory, says "We were astounded when we discovered that this small stunning plant had such a large genome ­ -- it's so large that when stretched out it would be taller than Big Ben.

"Some people may wonder what the consequences are of such a large genome and whether it really matters if one organism has more DNA than another. The answer to this is a resounding "yes, it does," and the consequences operate at all levels from the cell up to the whole organism and beyond. In plants, research has demonstrated that those with large genomes are at greater risk of extinction, are less adapted to living in polluted soils and are less able to tolerate extreme environmental conditions -- all highly relevant in today's changing world."

http://www.sciencedaily.com/releases/2010/10/101007120641.htm

You're right. That's fascinating and unexpected.