Most RJ-45 connectors (without a boot on them)… The connector only fits one way, the orientation is clear on both ends while holding, looking or even by feel if you have to do it blind and it locks into place easily. Only issue is how fragile the locking part is, which boots are supposed to help protect but make more difficult to use.

I like reversible connectors like lighting and USB-C but I find them too small and fragile in general and they are not very satisfying to connect.

I have a special hate for connectors that are HARD to blind connect or even tell at a distance like USB-A, HDMI and Displayport which are ether rectangles or slightly not rectangles that are close enough that is hard to tell in the dark behind a device.

I have a strong dislike for connectors with thumb screws, but like locking connectors like Centronics or as noted RJ11 or RJ45.

Jumper wire into bread board.

Runner-Up: Paper clip into Socket

• Best insertion: Displayport Locking
  • Runner-up: Ethernet (RJ45), Apple 30-Pin (Locking)
• Best removal: Magsafe 3
  • Runner-ups: USB-C, USB-B 3.0
• Best differential pair connector: Lightning (because it’s so consistent feeling)
  • Runner-up: USB-C
• Best residential AC plug: British BS1363 (Type G)
• Best lightbulb base: Bayonet B15s
  • Runner-ups: GU10, GU24, Fluorescent Bi-pin
• Best audio port: 6.35mm TRRS (1/4")
  • Runner-ups: Banana Jacks, Neutrik SpeakON
• Best video port: HDMI
  • Runner-ups: RCA Composite/Component, DVI, BNC, USB-C
• Best device-internal connector: JST GH series
  • Runner-up: any miniature mezzanine connector

• Worst differential connectors: USB micro B 3.0, any ethernet cable with a bubble boot or broken latch, mini-HDMI, micro-HDMI
• Worst HF connectors: Coaxial, all miniature HF wire to board connectors (holy crap the naming is inconsistent) i.e. UFL, IPEX
• Worst audio connectors: cheap 3.5mm, spring clip terminal, binding posts (especially plastic knob ones)
• Worst residential AC plug: Europlug
• worst device-internal connectors: wire soldered through-hole, any Molex connector or power connector inside a computer

My first is RJ45, it’s so clicky.
After that is everything held together by magnets. I bought a cheap magnet microusb cable for charging my headphones. It’s like magsafe but way weaker.