In the movies aliens usually land in the country which made the film ;-)
But seriously, where would they really land? Depends on how much research they did before but here are some possibiliites
1. In the ocean - most of the globe is water so makes sense to control the biggest resource (also they might like fish or be aquatic aliens).
2. Somewhere to take central control of the biggest landmass which is Eurasafrica, so probably middle east or perhaps high ground just overlooking it like the caucasus? Harder to counter attack.
3. If they did research and intercepted comms etc maybe China (biggest population, has a leader who rules for life rather than transient weak leaders elsewhere so ultra powerful).