Just grab Media Player Classic - Home Cinema. This player has native support for .mkv and h264 (among many others). It will play just about anything, and has no problems with subs. Works fine with HorribleSubs stuff, specifically.

I've been using it for quite a while (also has DXVA) and figured it would help a few of you. You can get it at:

http://sourceforge.net/project/showf...roup_id=170561

I'll check this thread and try to help out if people have trouble using it.