I really liked the Seidio Surface with the clip that covers the screen. Had one for my Blackberry Storm1 which survived physically longer than I was able to stand the limited phone. I was disappointed that Seidio chose to not make the Active or Rugged or whatever it is marketing calls it this week for the Charge.
Then I went with the extended battery, and even the Seidio surface does not fit any longer. I've been tempted to cut a hole for the thick battery to hang out, but am hoping Gingerbread might let me return to the stock battery.
For now have been using a Nite-Ize Sideways Clip Case LARGE. Which works well. The size large is important. You can squeeze the phone into the medium, but you are liable to flip it across the room as you draw it. The large fits just slightly snug. The Nite-Ize belt clip is a solid secure grabber as well. It is more likely to still be on your belt even as you do yard work.
Seidio's lack of support for the phone has been quite disappointing. Hard enough to choose a phone without trying to factor in who makes what cases for which battery configurations. I'm not sure Seidio appreciates that selling people on their case designs - but then cherry picking the phones they fit them to is a recipe for disgruntled FORMER customers.