This is something that bugs the crap out of me and just thought Id see what others think.

Say you live in Hornsby NSW. We have people put their address down as Hornsby, Sydney, NSW. The bit that bugs me is their postal address is not Sydney, unless their postcode is 2000, then don't use Sydney in your address. You may live in the Capital City of NSW (sydney) but its not your postal address.

The other thing is people who live in units. Is it really worth putting in U10 / 16 blah st, or Unit 10 / 16 blah st. Everyone knows that your address is 10 / 16 blah st. The / or , tells everyone its a unit

Due to the fact that I write out a crap load of addresses daily to get peoples orders out, I think its something thats allowed to bug me.

Yep, that's right Faz. I work with a lot of address's at my job also. I always put 10/16 Blah St, whether it is a unit, shop, factory etc.
I don't understand the other thing though. I never put Melbourne in my address because when an address form says "City", I put the suburb name. I figure American's must use city name , rather than suburb.

I'm guilty of saying Perth where it says 'City' even though I don't actually live IN Perth, followed by the suburb Ever since I moved out of the country town where it didn't have suburbs I get confused sometimes

yeah your allowed to let that bug you faz.

the only thing that bugs me is when it says suburb and i only live in a town nowhere big enough to have suburbs haha

the town is the same as suburb or city. I get it all the time, they give me suburb in cairns, why I dont know