I've heard a few people use television ownership as a marker for the poverty line, although it does exclude the small minority of us who actually prefer not to have a television. For the US, an important marker could be whether or not you have access to healthcare, although the healthcare system is weird and complicated. I have limited access to healthcare myself due to disability; were I seriously rich, I could probably get around many of the problems. On the subject of disability, there are basic minimum standards of living that also apply, and again you're disadvantaged unless you're wealthy enough to pay for all of the care that you need (the care provided by the state is usually wildly insufficient). I'm talking about people not being able to bathe for weeks on end, that sort of thing. Being able to afford to heat your home sufficiently is another common poverty marker.

If there are still people sleeping on the streets or dying from causes directly attributable to poverty (e.g. starvation or hypothermia), I don't think anyone can say a country doesn't have poverty. What level of poverty and how many people suffer from it is more to the point.