Awesome!
First one is definitely worth watching.
Two is fun and entertaining, but is a far cry from the tone of the original
Three is bargain bin
Four is a bloody fun mess, but only if you really dig the series
One is great and mostly since it shows how devastating PTSD is 25 years before people really knew what PTSD is.
Two is probably my favourite: super-jacked Rambo, an Asian hottie, and The Man (x2, a Russian and a 'Murican), and cool Russian military toys.
Three was cool, mostly cuz they guy is like "I can see you have no experience in war, do you? Come on, DO YOU?". Little does he know the shit Rambo has seen and done.
Four is amazing, not for the "bloody fun mess", but for shedding an extremely disturbing light on what's actually going on over there. It's heartbreaking what civilians are going through. The previous movies dealt more with law/military "enemies" whereas this one hits way closer to home in that these are just people trying to live their lives.