The reason one sees Hiroshima and Nagasaki mentioned far more frequently than the Tokyo fire ride of 9-10 March 1945, is that those two attacks were the only use of atomic weapons. And, those two bombs caused Japan to surrender, while the Japanese had previously fought to the death, almost to a man, and when the numerous fire raids on Tokyo and many other major Japanese cities had not.
Since then, there has been an unofficial ban on the use of atomic weapons by all nations that possess them, to where they remain today to be a tool of deterrence, not offense, even though conventional weapons can produce the same damage as a low yield nuclear bomb. Consequently, the only use of atomic weapons tends to get mentioned a lot. It is the unconventional and almost taboo nature of the nuclear bombs that keeps them front and center.
Hiroshima suffered around 80,000 deaths, while the Tokyo fire raid is estimated to have killed upwards of 120,000. One fact not often mentioned is the amount of damage done: Hiroshima had roughly four square miles destroyed, while the fire raid on Tokyo destroyed 16 square miles.
Four times the damage, with 1.5 times the casualties... one reason for this difference was the slowness with which the firestorm arose in Tokyo, taking a few hours to reach full power, giving many residents time to get out. The atomic bomb unleashed it's full fury in an instant. And part of the reason was the residual radiation after the attack... invisible, and the dangers of radiation were unknown to most people at that time.
While the US had dropped leaflets over the two cities and several others warning of impending raids and advising the people to leave, there was almost no warning on the day of the attack, other than three bombers appearing over the city during daylight hours, thought by many to be just photo recon, as opposed to the 300+ bombers that attacked Tokyo at night. The fire raids were all carried out at night, as General LeMay had established that Japanese antiaircraft methods were not nearly as effective at night.