I live in the US, and honestly I think it is the best country to live in. Not in the "we are better than everybody else" way, just I love my country. For all the problems and issues that people complain about, most of them boil down to "first world problems".

I have a nice townhouse, that I was able to afford after working hard in school and getting a good paying job. I am lucky to have a good education, and parents that gave me a wonderful environment to grow up in.

I have a computer, and access the internet - where I can do all kinds of things that were unimaginable only 20-30 years ago. I can drive to the grocery store and buy pretty much any food that I can think of to eat. I have AC in the summer, and heat in the winter. Some times, you just have to appreciate the little things, ya know? lol

The US recently legalized gay marriage, which was a big deal for me because I was able to marry the love of my life. We have been together for 8 years now, and now married for 1. It is cool that we have progressed as far as we have on this issue recently. (Not to say its perfect, but you know..)

I really feel that today is one of the most exciting times to be alive. There are tons of things going on, and I feel like I am right in the middle of all the excitement. I'm sure there are lots of other great countries too (which I look forward to reading about in this post), but I feel the US is just right for me :)

[Edit] I did realize the question asked for both "best" and "worst". I really should have caught that, seeing as I created the post, lol.

As far as the worst part, I would have to say it is all the hate. There are a lot of groups in the US that do not get along, and it goes way past the point of civil disagreement. If we could get through that issue, I feel the country would be a much better place.