The following are vendors I have used and can recommend.

GetSnus, the only US based snus operation worth mentioning that I'm aware of. Limited selection in comparison to their counterparts in Sweden but prices and shipping costs are great. 3 to 4 days coast to coast every single order.
EDIT 5-13-2010
GetSnus is now owned by Northerner. Prices for both product and shipping IMMEDIATELY jumped 20% on average.

Sad day...

SnusCentral, better prices than "comparable" vendors in Sweden. Very focused on customer satisfaction and somehow they manage to get my orders to me in 8 days and less whereas their counterparts have never gotten an order to me in less than 12.

The Northerner, Sweden, Big selection but spendy, 12 to 15 days ship to Oregon and customer service tends to be spotty.

snuff.me.uk, Based in the UK, one of the few in the UK that accept US issued Credit Cards. The only place worth looking for Samuel Gawith bulk or for that matter those silly damn tap boxes that SG insists on using.

Wilsons of Sharrow Online, Direct from the mill in Sharrow UK. Unfortunately US orders must be paid for with check, money order etc. and Wilsons will be tacking on an additional $6 charge for taking checks. Pain in the ass but if you've the time the prices are such that it's the least expensive way to get Wilsons bulk at the moment.

Mars, Full service tobacco vendor based in Pennsylvania U. S. of A. No snus but he's got the lowest shipping cost of any snuff vendor, comparable pricing but somewhat limited selection.

Toque Shop, Free shipping worldwide, price per gram is good, Toque products only.

The following are snuff vendor powerhouses, they are still in business but as of this writing are somewhat low on stock due to relocating from the US to the UK. Thanks a lot Washington!
NicotineRush, I do like this one!, Huge selection, 3 days from Florida to Oregon.

MrSnuff, Neck and neck with nicotinerush for price, selection and service.