Right, this is my niche! I find myself bouncing between paranormal romance and mystery a lot, and the ones that weave those threads together are always the most memorable. They’re not just about the relationship or the spooky case alone; it’s the tension of solving something dangerous while navigating this new, impossible bond. A classic that nails this is the 'Charley Davidson' series by Darynda Jones. The premise is that the main character is the Grim Reaper—a private investigator who sees ghosts and helps them cross over while solving their murders. The romance with this brooding, mysterious son of Satan (literally) unfolds across the crimes, and the mysteries are genuinely clever, not just backdrops.
For something with a grittier, urban fantasy feel, Ilona Andrews' 'Kate Daniels' series fits, though the romance is a slower burn. The post-magic-apocalypse Atlanta setting is a mystery in itself, full of unraveling ancient secrets and political conspiracies, and Kate’s dynamic with Curran, the Beast Lord, develops while they’re constantly thrown into life-or-death investigations. The mystery elements are baked into the world-building, which I appreciate. A newer author I’ve been hooked on is Kristen Painter, especially her 'Nocturne Falls' books. It’s a lighter, cozier take where the town is a supernatural tourist trap, and each book features a resident solving a magical mystery while finding love. It’ compressed dark and fluffy perfectly.