I like Zvezda - but mainly their 15mm or 1/100 ranges. They're not growing particularly fast - they seem to have moved away from them a bit, but they're superb for Battlegroup if you can find a suitable Russian eBayer.
In the U.S. people tend to charge a bit too much, but if you're willing to wait 30-60 days (

!) you can get a load of 15mm kits for cheap. Their newer stuff is much better than the old stuff, but $3-4 for a Tiger tank or Elefant, or an IS-2, etc. is excellent. Also, being able to buy kits individually is excellent. In a time when Flames of War/Battlefront want $50 for four Tigers...getting the same for $12 is tough to pass up.
I see a lot of reviews and built videos of their larger 1/35th proper models on YouTube - that seems to be the direction they're heading.