Did someone mention me? The Grand Sophy was the first Heyer I read as a teen and remains my favourite (I skip the anti-Semitic passage on every re-read). A friend had found a paperback edition from the late 60s on her aunt’s bookshelf and she and I later read the other three her aunt had (Powder & Patch, These Old Shades and Devil’s Cub). A couple of years later they started being reprinted in paperback in the U.K., I found more in various libraries so that within a few years I had bought/borrowed and read all the historical ones. I read one of the detective novels but guessed the murderer half-way through so didn’t try any of the others.
A few years ago, a secondhand bookshop near me was selling around 10 or so Heyer first editions for £5 each and I bought the lot. I passed on my duplicate paperbacks to daughter of the friend who had lent me the first one. The bookseller told me they often received collections of Heyers from house clearances etc as those who read one, then started reading/collecting the others.
To answer the original question, my top 5 mainly based on the number of times I’ve re-read them:
The Grand Sophy
Frederica
Sylvester
Friday’s Child
Devil’s Cub/Cotillion
That’s six but Cotillion can only be appreciated after reading several others to see why Freddy is a different type of hero. Devil’s Cub is the one hardest to justify but Mary is sensible and I developed a crush on the awful marquis when I first read it. So much so, a couple of years ago DD and I went to Paris and I ended up choosing a hotel close to Rue St Honore simply because that is where Avon House was.
Also honourable mentions to The Quiet Gentleman, Sprig Muslin, The Reluctant Widow, Venetia, False Colours and The Talisman Ring. I haven’t re-read The Unknown Ajax or The Foundling recently and plan to do so soon.
There was an audio mini-series of The Grand Sophy released in 2019. The story and particularly the ending is truncated but it was a fun listen: https://open.spotify.com/show/3CQupXfXvSugH7xPRPj1eW?si=9A27hVVPSLS5lamIJt1zGw