The best playable characters in a fighting game aren’t always the most popular, particularly if that game happens to be part of a franchise that has been going strong for more than three decades now. This appears to be the case when it comes toMortal Kombat 1, with the likes of Sindel, Geras, and Shang Tsung quite far down the pecking order despite featuring in the S+ tier ofSonicFox’sMK1tier list.
That said, there does appear to be some correlation between the best and the most popularMortal Kombat 1characters, especially when it comes to some of the OG kombatants. It also helps that the devs are constantly making changes behind the curtain, which has led to certain fighters getting much more use now than they did when the game first came out.

The following list ranks every kombatant based on the number of people who have searched for information about their fatalities. Though it is by no means definitive, it should still provide a pretty good indication of the most popular characters inMortal Kombat 1.
37.1%

6.8%
6.4%

5.5%
4.6%
3.4%
3.1%
2.9%
2.5%
2.2%
2.1%
1.9%
1.8%
1.7%
1.6%
1.5%
1.3%
1.2%
1.0%
0.8%
0.7%
0.6%
Observations
It’s important to note that people paid extra for kombat pack kombatants like Homelander and Omni-Man and so are far more likely to spend time playing with them than the average fighter. That said, Quan Chi ranks below some of the base roster, so this may only extend to guest characters. It’s also interesting to see that most of the ninjas rank highly among the most popularMK1characters despite Scorpion and Sub-Zero being B-tier or lower in many people’sMortal Kombat 1tier lists.
Given his importance to the main storyline and his status within the series' lore, it makes sense that Liu Kang would be one ofMortal Kombat 1’s most popular kombatants, as does the high placement of Johnny Cage; who many consider to be the best fighter in the game. Him being an OG kombatant likely helps too, with many of the top spots populated by characters who debuted in the first fewMortal Kombatgames.