http://www.tacticsarena.com/
Does that count as indie game? I played it when the guy first made it and it was alot of fun. However once people started getting rare units, or lots and lots of units it became too unbalanced and was more about what units you owned instead of strategy. I'd play it once in a while still if he made a server where everyone has the base starting units and that's it.
You guys are the first people I've heard say Enclave was good. A friend and I played the shit out of that for like a month, I thought it was great. Challenging as hell but doable once you practice alot...I thought it had the perfect challenge balance.