There have actually been a few commercial Rambo knives over the years.
But so far most of the swords I liked have been sold in some form or another. Sword from Sleepy Hollow was one. There is actually a very good Zelda Master sword sold on ebay these days. It's much more fragile than I like but it is still a very accurate replica. But they really should try harder with the He-Man and Thundercats swords, the ones on ebay suck. Crappy polyresin hilts on tap welded rat tail tang stainless blades. ugh......
What I would like is an actually accurate and well crafted Hanzo Bride sword, Green Destiny, Carbon steel Sword of Omens (for a cartoon sword it is actually kind of a nice broadsword) and maybe a carbon steel Connor Macleod Masamune.
And the sword from the cover of Zelda 2 on NES too, but I just like Zelda stuff in general...