The big trend right now is "True Bypass"; completely removes the audio circuit from the signal line (since electrons flow in a forward direction) and sends it through a jumper across two of the poles on the switch. For most purposes, a 3PDT switch is needed for an LED status indicator to know when it is on or bypassed. The only things I have negative to say about it is: what happens when you're running long cables? A buffer? True bypass buffer (that's not ironic at all)?. Every inch of cable degrades your signal each little bit, and for true bypass, you need the most minimal amount of signal loss. But in these "True Bypass" switching systems, your signal has to go through an (in my opinion) unnecessary extra inch of wire before it can actually be bypassed. Then, if you're having to run off of batteries, it leaves the battery on, causing current draw of the electrons (the ones that compose your signal) to keep the battery draining even when it's off. Plus, the cost of those 3PDT switches is one of the additional negatives to me.
My solution is a different method of bypassing, one of which I believe to be the most effective and electronically correct; so I'll call it "Honest". A single DPDT switch works as an SPST switch for the battery signal into the circuit to turn off the current draw from the battery (so that it could stay in without drawing current, therefore not moving the electrons towards the circuit, and preserving the battery's life), while the signal is fed to the end path of the circuit, where the circuit would be in parallel to the dry signal (or so to say). The LED can be put on the path of the battery (not in series, but off with a resistor to ground). They are more cost-effective and easier to find. :) No tone suckage will happen, because there is no extra jumper to pass through, no electrons moving towards the circuit (since the battery's off, there is no current draw tempting the elcetrons to flow that direction).
*Special Note!!! DO NOT send the second lug of the battery's switch to ground. This will recomplete the circuit of electrons flowing to the battery, and cause it to drain, even though it is only going back into itsself. Just thought I'd help out with that. :)