What is comes down to is use any type of formatting as opposed to no formatting. Too often people crank out code, do not comment it and do not format it. This applies to every language. So far as SQL syntax goes, what irks me are:

* No use of spaces.

* Obscure use of aliases. If you have 4 tables all aliased as a,b,c,d then you are making life hard for someone else.

* Not capitalizing operations or reserved words.