Every guitar I own preferably...
locking tuners
low friction string tees (preferably none at all)
1 11/16 or larger low friction compensated nut
stainless steel frets
a flat enough radius not to fret out with low-medium string action (preferably compound radius)
A sufficiently thick neck (no wizards, standard thin is marginal)
A satin finish or no finish if unnecessary
Strap locks
A fully intonating bridge (preferably with individual saddle height adjustment)
Either awesome humbuckers with decent single coil sounds through the use of coils taps, or awesome single coils with decent humbucker sounds with series/parallel option, or some other versatile setup like firebird pickups (hums with single coil qualities), P-90s (single coils with hum qualites), P-rails (jack of all trades), or combinations of singles and buckers like an H-S-H or similar.
In short, I think every guitar should be in tune and intonated, and STAY that way once new strings settle, regardless of whether it's got a tremolo or a hardtail. It should be easy to play without slowing you down and cramping your hands and fingers. It should have its sonic strong points but be able to cover other sonic territories in a pinch so that I don't have to take multiple guitars to a gig.
I can't do all of these things with with every off the shelf guitar, but there are off the shelf guitars that I like that don't have all of these things, so I do what I can. It sure helps to have a fender scale neck pocket and a pickguard.