Odesa, Ukraine - far from me. Even though, it's near the sea, I would prefer going to capital city of Ukraine, rather than to Odesa again.
Oh, and also because of how the venue is made for such shows. I don't know how it is in other venues, but there one could buy the cheapest seats, and without any problems go to the most expensive ones, as there were no barricades between sections.
Also, Russia. I know many will hate me for saying this. But they played a lot there, and only once in Ukraine, and as Russia is always like a rival country for us - I would like Linkin Park to not play there anymore.