Fiesta. The XTR (or sedan if you want to spend less on the same car... the normal hatch is not as good) is a safe car (important when you are on the road a lot), quite economic, it's young and hip.

Polo sedan is technically outdated, though still a decent car. City is outdated. Focus is modern, yes. But the Fiesta is more modern than the Polo sedan (especially the Fiesta sedan is) and the City. Even if those were released later.

Another good choice would be the Toyota Prius C.

@cybermaster: From what my dad told me (and if I recall correctly) he used to do maybe 1 million km on a car before he'd get the next, though his car would need a new engine in between. That was in the 60s-70s IIRC. He used to drive Merc diesels. They lasted forever.