Interesting, as it demonstrates that too many classics are missing from 4K, such as 'John Carpenter's The Thing', 'The Exorcist, 'Dawn of the Dead', (the Romero cut) - out in November 2020 on UHD bluray), 'Night of the Demon', any of the Hammer output ('(Horror) of Dracula, 'Brides of Dracula' or the excellent 'Frankenstein created Woman' would be great places to start) and something from the Universal vaults, such as 'The Black Cat', or the more famous 'The Mummy', 'Bride of Frankenstein' or 'The Wolf Man'). If horror anthologies need dusted off, I'd go for 'Dr Terror's House of Horror', as my number one pick.
Horror comedies are harder to recommend, but, again, one can't go wrong with 'Abbott & Costello Meet Frankenstein' (featuring Frankenstein's monster, Dracula and the Wolf Man), 'Carry On Screaming' (a superb send up of Hammer and Amicus movies) or the classic, 'Ghostbusters'. I'd also consider 'Evil Dead II' here.
Of the 4K discs, I'd suggest 'The Fog' (effective ghost story) and 'Alien' (a haunted house story, set in space, and a stone-cold classic) as worthy contenders not on the list.