Things I buys when I go to the US:
- Clothes - particularly US / European designer labels are much cheaper in the US (Diesel, Hugo Boss, etc, etc)
- Food - Hot sauce (great idea), beef jerkey, chicken wing mix (all done much better in the US than Aus) - make sure you declare it on the way in.
- Electronics - anything is much cheaper in the US than Australia. Just be careful of Voltage and plug - and of course Customs if it's worth more than $925.