Best Equipment

[Twist]

I just bought a mexican double ended bag for fun, But I was wondering what you guys think the best piece of equipment for training boxing/muay thai is. If you could only have one bag or whatever, what would it be and why?

[CMB]

Punching bag, because its the most versatile piece of equipment.

[Times Roman]

I was a tae kwon do nut in my late teens / early twenties.... too slow now, so I just go for the heavy bag. If I can't take a mate out in 4 or 5 blasts to the solar plex and liver, then it's quits, and I'll buy the first round!