Well to be fair, I do use fallthrough in so far as I group cases that are the exact same, but fall-through with slightly different logic is very bug prone and difficult to spot when it is deliberate or an accident, so I basically never use it.

Perhaps some languages conventions are different, but for example Douglas Crockford on JS:

> "switch Statement

A switch statement should be avoided, but when used should have this form:

   switch (expression) {
   case expression:
       statements
   default:
       statements
   }

Each case is aligned with the switch. This avoids over-indentation. A case label is not a statement, and should not be indented like one.

Each group of statements (except the default) should end with break, return, or throw. Do not fall through."