Same thing here. Happened ever since the last patch. Played a bot game today on this new patch and it froze on me again. Given the nature of the crash it wont generate a bug report sadly.
Symptoms/nature of my crash:
-Everything on screen freezes in place. Like a snapshot.
-Game becomes unresponsive.
-Cannot alt-tab out of the game client.
-SOMETIMES the windows Key will work. Attempting to run any program from these menus will launch selected program, but will not remove/switch from the frozen game window. (essentially running the program in the background of the frozen game without being able to access it; like task manager.)
-Only way to fix the frozen game is to forcibly restart the computer.
I just ran a self repair before posting this, so hopefully that fixed it. It would take time to know for sure, as the freeze occurs at irregular intervals. Maybe once a day; though it has happened to me in 3-4 games in a row on one occasion.
I know on my end I had a direct-X update, and a graphics card driver update over this same period of time. I'll be looking to roll those back if the repair didn't work I think.