Desktop Charger: I have had various chargers from Anker over the years (pre-IQ days), but since I have the Nexus 6P, this has been great for my desk:
Bluetooth Speaker: Even though I have purchased several over the years, this is my preferred speaker (A7909). I don't have PC speakers anymore, and this is powerful enough to get the job done for most of my uses (otherwise I use headphones).
External Battery: Again because I have a USB-C device, this battery is great so far. My only compliant is its large size, but the pros definitely outweigh the cons.
External Battery Runner-Up: Due to it's smaller size, I really like this battery: