Edited by: Tekota on 06/09/2011 17:10:56
I'm sure there is a list out there someplace. Or in the stickies.
Jita, Rens, Amarr, Dodixie.
They're the ones that matter.
Oursulaert also kind of a mini hub.
For many of the others, "hub" could perhaps be too generous. Pick an item or three when in an out of the way region, look at the market buy and sell orders to see which system has the most volume. Bingo, there's your hub.
EDIT: In fact yep, it was in the stickies - http://wiki.eveonline.com/en/wiki/Market_resources
under the section "General Market Information Sharing"