Vertical games, should buttons go on left, right, or both?

[rackoon]

Well like the topic says I am working on a three sided cocktail cab and have 22" of control panel for each side and I was wondering if I need buttons on both sided of the joystick to accommodate all games. I have the room for it that's for sure. 

[DaveMMR]

Heh!  You've got the room now....   but it goes quick.

You can never go wrong with buttons to the right of the joystick.  That's pretty much the standard and no one's ever complained (except for the left-handed possibly). 

If you do have room and you're using three or less buttons per player, then putting them on both sides wouldn't be horrible.  A lot of older games did in fact do that.