2017, 2018, 2019, the committee has been on a tear, picking interesting, slightly-less-mainstream but still really defensible winners. E.g. Banerjee, Duflo, and Kremer (2019) are unusually (for economists) engaged in the real world. Nordhaus and Romer - both considered on the quirky end of mainstream (though Romer's textbook of course gave him total mainstream cred, look at the rest of his career). Thaler (2017) had a huge body of writing that verged on popular economics. When I was an economist, each of these really shook up the way I thought about what was possible in the field.

Milgrom and Wilson is... expected. I mean, auction theory has been very influential, but I think Roth + Shapley (2012) just recently covered more fun intellectual predecessor and successor movements to much of Milgrom and Wilson. Classic theory-heavy work that has had practical influence as well. Arguably, their emphasis on supermodularity was a deep theoretical influence on follow-on work, so I have to count that as high impact. But it does feel a little less exciting than past awardees. Maybe just because we've lived with auction theory for so long now?