The subtlety of the handshake..
It goes beyond the crush/dead fish, there's another dimension that I'm surprised nobody has mentioned yet.
There's the rotation aspect - without crushing, if you rotate your hand so it is on top, then you signify that you think you're superior. If you're soft and let your hand go under, then they're probably right.
If, instead, you rotate purposefully so that your hand is on the bottom (leaving no doubt that YOU did it, not them) then everyone wins. Your initiation of the turn gives you decisiveness and strength, and the fact that you have placed the other person above yourself is very respectful.
If the other person matches you in trying to rotate so your hand is above theirs, then you have a pretty reasonable measure of each other.
Of course, the speed, control and degree of the rotation leave plenty of room for personal expression. And, as a bonus, if it's a lady who's hand you're shaking, you're then in the perfect position to go for that lingering and soulful finger kiss (if appropriate

)
Nothing worse than the crash shake though - you know the one where the other person is so keen that they smash the webbing of their thumb into yours. I can usually pick the crushers before the event, and match them. I'd never initiate a crush shake though - it's a bit too red-neck for my liking.
Anyone figured out the Masonic secret handshake yet?