Man, this question hits different after re-reading 'The Handmaid's Tale' last month. That book is the blueprint for me—Offred's inner world is so much about stolen moments of memory and desire against a regime that wants to erase both. It's not a swoony romance by any stretch, but the rebellion is in every whispered thought of her lost husband. The romance is aching and melancholic, completely woven into the fabric of resisting Gilead.
For something with a more central, driving love plot, I'd point to 'Legend' by Marie Lu. June and Day's dynamic is fantastic because their initial alliance is purely tactical, born from needing to survive and overthrow a corrupt system. The romance builds from shared purpose; they fall for each other's minds and resilience first. The rebellion plot isn't just a backdrop—it's the engine of their relationship.
A newer one that did this well was 'Iron Widow' by Xiran Jay Zhao. Okay, it's more sci-fi/fantasy than pure dystopia, but the setting is a brutally oppressive patriarchal society. Zetian's primary drive is vengeance and systemic overthrow, and the polyamorous relationship that forms is a direct, strategic rebellion against the society's norms. The romance is fierce, complicated, and entirely in service to the larger goal of burning everything down. It's less 'love conquers all' and more 'love as a revolutionary weapon,' which feels very fresh.