For years, i played a Stratocaster. Not because i loved it, but because it was bought for me as a gift by bandmates brand new in 1988.
It took a long time for me to finally figure out what exactly I wanted/preferred in a guitar. While I knew that some guitars felt better in my hands than others, it wasn't until last year that I actually applied science to figuring out how to identify my preferences. After that, it wasn't hard to understand what I was looking for.
Scale (24.75") and neck profile (Fat 1958 Les Paul) were my number one comfort factors. Adding to that was a 12" radius and short frets. My 2016 Gibson SG T Series has both as does my Von Herndon prototype DoubleNeck. These are my preferred guitars.
However, I've also discovered another obscure detail...
While I agree with Spectre that building your own guitar is very rewarding, I've also discovered that what I want in a guitar simply cannot be created from factory available components - it could only be built from scratch.
My ideal guitar would likely be a neck-through Firebird with an EDS-1275 (12 string profile) neck, but strung with only 6 strings. That's a profile a full 1.125" thick at the nut and 1-7/8" wide.
This is based on a comfort and preference of how my 12 string feels in my hands when playing it.
Not really wanting to go the full, one-off custom route again, (time & $$$) I've found myself quite content with my S-G and my double neck, to such a degree that I don't want any other guitars and I sold off/gave away everything else.
I can play any guitar, but there is a comfort and a speed in my playing with my "Thing 1 & Thing 2" guitars that I don't experience with other guitars.
The larger physical size of the double neck causes me to play it with greater confidence and abandon, because it doesn't look like a toy on me...that's a huge factor for me!!!!