Most era-ambiguous year you can think of?

I would say 2009. Perhaps not a genuine 00s year but definitely not a full on early 10s year either(I don't get why people say it is an early 10s year, it didn't feel anything like the 2010s and didn't even feel much like an early 10s year for that matter either). It's in it's own bubble. 

Honourable mentions: 2013, 2016