+1 to MoreBeer and AHS. Northern Brewer is running 7.99 flate rate shipping right now as well.
Just keep in mind that the lower shipping prices may mean higher prices on their items. When I'm buying online I try to buy several brews worth of items. I then price everything out at Morebeer, Midwest NB, AHS and Rebel Brewer (including shipping) before I decide where to get my order from.