Mustang Cobra, no. I see 4.5 at best. E55? Comparable. 997? BS. Same times. Carrera S, perhaps a tick faster. NOT significantly. GT3, I see as high as 4.8 0-60, some as low as 4.3. Again, NOT significantly faster.
W/ the M5, you have to be joking. It ain't gonna hit 4.1, dude. It'll break 5 and that's about it from a car that size even with the V10. 4.5 would be great, but that's, again, ON PAR with the NSX.
But, either way, you've failed the test. NONE of these cars are significantly faster. In fact, the fastest NSX times are faster than some of the slower times of these cars, excepting the Vette and Viper. People could actually argue that the NSX is a tick faster, using 0-60. But, it's inarguable that they are VERY close to one another and NONE of them that you mention, except for the big American muscle, is SIGNIFICANTLY faster and under 80k!.