Late to this thread as usual, but I might as well submit mine:

My Fender Telecaster. It’s a paradigm of simplicity, reliability, playability, and tone. From the original barrel-style string saddles to the 2-pickup/3-way switching system to the high-output single coil to the bolt-on neck construction to the straight string-pull head stock, there is no better guitar on the planet. What’s even more impressive is that it was designed by a non-guitarist and was one of Leo Fenders earliest designs (and is largely considered to be the first mass-produced electric guitar). I own far too many guitars of various styles and cost, but I nearly always perform and record with my Tele. It’s my proverbial desert island guitar.