For me, if I am making mp, almost always SFIC bases. BB sells them, although I usually buy in larger amounts from Wisteria Lane. I have had problems with BB's packaging, and WL's SFIC is as cheap or cheaper in bulk, plus I like their extra hard clear base, and shipping is fairly cheap to me b/c I am close to them. I sometimes use other bases if I am intent on a specific effect (ie; super clarity) but SFIC's ingredient list is so good, one of the few MP bases that, if you were a seller, you could actually sell as just "soap".
There are a couple of other v. high quality MP bases on the market, eg, New Directions Aromatics (NDA) sells a non certified organic base for a very good price. I have found that one to be very cloudy, though, and NDA has a $100 minimum, which is kind of a pain. Also if you are trying to figure out/compare brands, NDA sells Stevenson's (sp?) bases, you might encounter that name in searches.
Edited to add: read the ingredient list on all the bases you are looking at. The fewer and more intelligible, the better. For me, reading the ingredients made determining the quality of a base much more easy and quick.
