If we're talking about spectacular performances then 2015-2016 Diego Rosa deserves a mention. Look at how he rode during those 2 seasons at Astana vs everything he did before or afterwards.
Got 3.5M over 3 years from Sky and only won Coppi e Bartali when he rode for them.
At the last Tour, I even thought Wout held himself back a lot to not look limitless. At least, except for maybe Gilbert in 2011 and Froomey in the first half of the decade, they showed weakness here and there in the 2010s, they've been blowing it up again the past two years or so.
I had the feeling Contador was up to something the whole 2014, but we never saw the full extent of it.