Hack Of The Night : Which stall to use in a public washroom

I usually try to avoid having a grumpy (#2) when I'm out in public.  I'd much rather be at home where I can have my privacy.  Sometimes that's not the case though.  You eat that certain something that just isn't sitting right, and it has to go now..  If you're out in public and you need to drop a two-sie here's which stall you should choose..