The Canon RF 135mm f/1.8 L USM not only makes a case for itself as the best Canon prime lens, but as the best 135mm lens period.
Canon EOS R6 Mark II + RF 135mm f/1.8 L IS USM
Canon RF 135mm f/1.8L IS USM hands-on review
Testing out the new Canon RF 135mm f/1.8!
Canon RF135mm F1.8 L IS USM - RF Lenses - Canon UK
Canon RF 135mm F1.8 L IS USM Lens
Canon RF 135mm f/1.8L IS USM review
Canon RF 135mm F1.8 L IS USM Review
A Review of the Canon RF 135mm f/1.8 L IS USM Lens
Canon RF 135mm f/1.8L IS USM Review & Sample Images by Ken Rockwell