The bikes of my yoof were pretty awful and I have no desire to ever ride one again. Apart from, maybe, a Panther 650 for an afternoon. The 80s were OK though.
My favourite of all time was a 2003 bike with a much older pedigree. A flat twin 1150. I liked the later IL4 K1200 for the sheer oomph of it all but for riding pleasure overall preferred the R1150 (it probably had less performance outside of my capability than the 150+mph K12

). The difficulty comes in explaining why - without falling back on 'engagement' or 'character'. I had a bike with the updated 1200 flat twin engine. The engine was undoubtedly better than the 1150 but I didn't like it as much.
There's only one bike that I've seriously considered having as a 'blast from the past' and that's the Suzuki 750GT. I know some say it handled like there was a hinge in the centre of the frame but - water cooled 750 2T triple? Well, yes please.
(I did quite fancy a Valkyrie but only because it had that daft flat 6 engine - but not in a big tourer. I suspect I would have loved it....for a week, then wished it was a Wing

).