It depends on what's available for me. I buy base malt by the sack from my LHBS. Lately that means anything MoreBeer has, they will order for me and sell at MoreBeer's price (less 10% AHA discount). That means I buy Weyermann, Great Western and Crisp (though lately I have been experimenting with Viking because it is so cheap). In the past, I have been happy with Best, Fawcett and Great Western. I didn't love Mecca Grade when I brewed with it, but that could have been because I was expecting one thing (full-flavored English style malt) and got another (sorta tart like a Belgian pale malt). I tried another craft malt called "Gold Rush" and liked it a lot, though it also was not as described. If I had only one base malt I could brew everything with, I would choose Fawcett's Golden Promise.