So I'm going to veer into my own specialist interest, and single out three Doctor Who writers whose works I find consistently sub-standard to the point that I find it astonishing that they get commissions. They are Eric Saward, Nigel Robinson and Keith Topping.
Eric Saward's overall contribution to the decline of Doctor Who in the period when he was script editor has been well chronicled elsewhere. Let me note that two of his three story novelisations, Doctor Who - The Twin Dilemma and Doctor Who - Slipback are simply dire. There is admittedly more merit in his Doctor Who and the Visitation, which I think may have been written first, before he thought he knew what he was doing.
Nigel Robinson deserves some credit for his editorial and political skills in keeping the Doctor Who books going over the years. Unfortunately he is a bad writer; there is no way to sweeten the pill. His novelisations of The Underwater Menace, The Sensorites and The Edge of Destruction, while admittedly not working with the best material of the black-and-white era, add nothing to the stories seen on screen; his early New Adventure novel is one of the worst of that sequence; his two recent Companion Chronicles have been underwhelming. I will admit that I thought he did better with his novelisation of The Time Meddler, but that was a richer seam.
Keith Topping wrote two of my least favourite Who Books, the Telos novella Ghost Ship which is the weakest of a range which was not terribly strong, and Byzantium! which has utterly anachronistic minarets in the city now known as Istanbul, in a story set 250 years before it became Constantinople. I have a couple of non-fiction books on the shelves co-authored by him, which are a bit better, but my suspicion is that he is simply a dreadful fiction writer. Seeing his name on the spine or front cover of a book would certainly determine me not to buy it.
This seems a bit ungracious of me. I should say that most authors who I have met or interacted with in person have been pretty charming, even if I don't actually like their writing and have said so in public; and I want to give a particular shout-out to Catherine Asaro, towards whose writing I have been consistently hostile, but who chose to engage me with grace and generosity (though I'm afraid it didn't change my take on her work).
That was a difficult one (as demonstrated by the fact that it took me an extra day). The next questions are much easier.
Day 01 - Your favourite series of books (with more than 3 in the series)
Day 02 - A book that you wish more people had read
Day 03 - Your favorite recent book
Day 04 - Your favorite book ever
Day 05 - A book you hate
Day 06 - Your favourite writer
Day 07 - A writer you don't like
Day 08 - Your favourite work in translation
Day 09 - Best scene ever
Day 10 - A book you thought you wouldn’t like but ended up loving
Day 11 - A book that disappointed you
Day 12 - An book you’ve read more than twice
Day 13 - Favorite childhood book
Day 14 - Favorite male character
Day 15 - Favorite female character
Day 16 - Your guilty pleasure book
Day 17 - Favorite trilogy or tetralogy
Day 18 - Favorite book cover
Day 19 - Best ensemble of characters in a book
Day 20 - Favorite kiss or love scene
Day 21 - Favorite fictional romantic relationship
Day 22 - Favorite ending/climax
Day 23 - Most annoying character
Day 24 - Best quote
Day 25 - A book you plan on reading
Day 26 - OMG WTF? plot
Day 27 - Favourite non-mainstream writer
Day 28 - First book obsession
Day 29 - Current book obsession
Day 30 - Saddest character death