Ah yes, how could I forget the finger pushups?

I only use knuckle press ups to work the exact muscles used in punching (more or less), but I dont find they do much for the hands, but like I said they're good for muscle isolation.

Tameshiwari (breaking) is also good, not for actual conditioning but checking your progress (not just conditioning but also power, focus, technique, etc).
The way of the warrior is a resolute acceptance of death. -Musashi