Who do you think came first to Cory - Shawn or Topanga?
For me, it's a really tough call.
I know a husband and wife are SUPPOSED to be number one to each other, and Boy Meets World highlighted this happening with the episode in which Cory repeatedly killed Shawn, but ... it's Cory and Shawn. Shawn and Cory. I mean, there is a 13 minute video on youtube of them acting like a couple! Topanga also got pretty annoying to me in the later part of the show. I wish it was Shawn. And I want to keep Girl Meets World out of this! It isn't canon, and I don't want the answer to this post to be hands-down Topanga because of how they write a sequel that came over a decade after Boy Meets World ended.
I pick Shawn. Cory might have tried to put Topanga first towards the end, but it was always Cory+Shawn. :-)
Video of Shawn and Cory couple moments:
https://www.youtube.com/watch?v=9jmgmYdHLxI