I've got some skeleton halberdiers, which are a good match for the old GW "armoured skeletons" - which is what I was after.
I've recently been painting some of the "Orcs of the Crimson Wave" (or something like that) as half-orcs in my plog. Afain, nice figures.
Used to have a bunch of the ancient Germans & Celts, also very good figures.
I picked uo some of the halfling archers, which are a little oddly proportioned, but otherwise clean sculpts. I think I'm going to pick up a few packs of the other halflings, from their "not-Bretonnia" range, which look better proportioned. I don't have any, but I've heard nothing but good things about the not-Bretonnians. They're supposed to be an excellent match for the mid-hammer Citadel metals.
Some of the other ranges look to be good, while others appear to be more mixed quality. But there are a lot of gems from BTD.
FWIW, Black Tree are almost always on sale for 30-40% off, but they are currently runnng a 50% off sale on most fantasy & historical. That's usualy the point at which I place an order.