Top 10, in this order:
1. Magnetic 1/4 driver bit. Get a nice hardened one that fits into an impact driver.
2. Ratcheting screwdriver, I use a Wera that contains the bits in its handle, but often the above attachment is in it.
3. Quality soldering iron
4. Fluke
5. Impact driver
6. Desolder gun
7. Ultrasonic Cleaner
8. Rivet Press
9. Ratcheting box end wrench makes flipper adjustment a breeze
10. Air Compressor