what is most popular project box size?

i know it's hard to answer, cause every project needs different sizing.
but i had an idea for an innovative project box design that i'm thinking to produce and sell.
so i would like to know what size should i offer first that most people need.
thanks everyone.

It would be nice to have a box in which the Arduinos fit. Problem is that you can't access the pins anymore. Maybe there is something to overcome this?

Altoids box. Only tall enough for arduino+shield (3cm?)

Something like this works for me: http://www.futurlec.com/ProjectBoxes.shtml
An example project using a similar box pictured in a few posts here: http://www.futurlec.com/ProjectBoxes.shtml

It may be helpful for some to know that a plastic Sucrets box pretty well. Like . . . http://www.sucrets.com/sucrets-cough.cfm

Biggest problem I have for most projects is that the standard size project boxes are too small to fit both a 16x2 LCD (horizontally across the shorter axis) and an arduino, and when you go the next size up, they're way too big.

!c