What is the fastest internet speed you have been able to achieve?

I'm just curious, I have seen a multitude of posts complaining about slow PSN speeds, and was wondering what is the fastest speed achievable? I have a 1000mbps connection (connected about a week ago), at first was only getting around 100mbps but after a bit of work I now get a stable 500mbps, though it fluctuates between 300-550 usually. My upload speed is 100mbps if anybody is wondering. I am still not getting what I actually pay for but it's much better than the 1/10 I was getting. What is the fastest speed you have achieved, and/or what is the fastest you have seen?

I am from New Zealand with Orcon Gigantic. Gigabit connection, get 500/150.