I'm sure this has been done before but it seems apposite, as I've seen several comments complaining of the forget-ability of this series' pro routines.

My favourites are old, from the days when the dances were (mostly) recognisable. They are:

Rebel Yell jive
https://www.youtube.com/watch?v=_n59-r5haCg

Black/white tango-foxtrot to Rolling in the Deep
https://www.youtube.com/watch?v=-xHiJj_19Yo

Erin & Anton's Moon River waltz
https://www.youtube.com/watch?v=mGK68O5Ro9Y

Katya & Pasha jiving/qs-ing to Caro Emerald
https://www.youtube.com/watch?v=B-fk78Qn4Po

The pastel-coloured group VW at Blackpool
https://www.youtube.com/watch?v=VOtAd8RSbJY

I can watch these over and over again

Matt and Aliona Samba.