Ordinary cigar lighter type plugs are quite badly designed, leading to poor contacts and overheating. The best type are the ones which positively "click" in to the socket - often referred to as "Hella" sockets. They're fitted in many trucks, so are widely available. Here's a Roadking webpage. In addition to surface mount sockets, you can get flush sockets.
Yes they certainly are better than your average "budget" tinned steel lined cigar socket. However, since a lot of items you want to plug in these days come with a voltage reducer fitted into the cigar plug or the device itself is mounted on the plug, it makes total faithfulness to Hella a very hard discipline to follow.
We have a surface mounted "Sutar's" socket in each cabin for plugging a set of "Daisy" cooling fans into and this pair of flush mounted ones over the chart table. They are just the surface mounted ones minus their black housings.
Those two replaced the original Hellas for the reasons above stated. the Hella to Cigar adapters were driving us mad and often the weight of the combined power unit and socket just pulled the Hella plug out so the phone or hand-held just didn't get charged.
I too have had a lot of trouble with 12v plugs and sockets.
Any vibration or slamming tends to cause the plug to break contact - pretty useless if it's your h/h GPS thats in.
So I looked into it - it appears that there are two types of socket and two types of plug.They both fit each other.
The 1st socket type is simply a metal tube and both plugs will eventually slip out.
2nd plug type is more complex at the bottom - it is the same design as a cigarette lighter socket - having flanges at the bottom that grip the plug.
However you need the superior plug which has a ridge at the bottom to coincide with this flange ( it's mimicking the cigarette lighter) - the cheap ridgeless plug will still fall out of the superior socket.
Am I making sense ?
I bought a triple socket and only one of them had the 'gripper flanges' the other two were plain tubes.
So, buy only plugs with ridges and sockets that are really cig. lighters - then it will work.
Even so it's a fudge - why isn't there an industry standard 12v p + s ?
What we have is a mish-mash and not good.....
.. on the triple are probably bi-metalic so that the actual cigar lighter will still work whilst the two "passive" ones are for power outs.
If sockets with the clip were available with a quality non ferrous finish I would swap all of mine straight off but until I find them the Sutars ones are the best around.