Haven't found it yet.
I won't buy any stick unless it can accept a Hand Candy balltop (groovygamegear).
I have Sanwa JLF's in my cab, but I cannot stand the super light original springs, so replaced them with stiffer ones (wanna say I ended up with 3 or 4 lb spring, but not 100% sure).
Didn't like the square gate, so switched to octagon, then to round.
Didn't like how loud the clicky switches were, so switched to optical switches.
Didn't like how they performed on 4 way games, so modified circuit to optical switches to adjust sensitivity based on game.
The shafts are also custom made to the exact height I wanted.
So I like my Sanwa JLFs, but there isn't much left of the original parts and I have around $200 in them.

Any future builds will be genre specific.
I'd like to do a shmup cab with a suzo 500
I'd like to do a 4-way classic cab with a joystick that uses a centering grommet instead of a spring.
EDIT: Sticks I have tried
Sanwa JLF (currently using)
Sanwa JLW (I like 'em in 4-way mode, good for manual switching between 4/8 way)
X-Arcade (not bad for happ style)
IL Eurostick (actually didn't like them as much as the x-arcades)
Seimitsu LS-56 (didn't use beyond testing out, IIRC I liked them for shmups but not for other stuff, sold them to another member for their dedicated shmup cab)
Original Pacman stick (feels like the first time, feels like the very first time.....)
Spitfire (JLF knockoff from groovygamegear. didn't care for them, they seemed to register one corner better than the other so ability to throw fireballs depended on which direction you were facing, upgraded my nephew's cab to two player with them)