My partner and I have a running joke that, when it comes to our baby, I have super secret magical powers. More often than not, our son will immediately stop crying, and his face will light up, whenever I enter the room, he hears my voice, or even smells me. So when we joke that our baby likes mom more than dad, it's only because there's a lot of evidence in my favor.
For example, I can interpret his cries and soothe him like no one else. Or how he sleeps best when he's touching me, and learned to say "mama" before he learned any other words. It makes sense when you consider that he hasn't been apart from me for longer than a few hours his entire life, and he's come to understand that I am his person. And of course, being baby's favorite has its downsides, too. I get less sleep and can't really enjoy anything even close to resembling "alone time," and my baby suffers from serious separation anxiety when I leave his view. So when I can get away from the house, I usually return fairly quickly and after my husband has called me a few times because the baby can't stop crying and he can't figure out what's wrong.
However, the disadvantages of being baby's favorite don't stop my husband from getting a tiny bit jealous when the baby reaches for me or refuses to eat anything that doesn't come from mommy's plate. To be fair, our baby likes his daddy, too, just for different things. No one can make him laugh better than his dad can, and they definitely enjoy their fair share of snuggle-time (when I'm not available, that is).
So, yeah, there are so many signs that I'm our baby's clear favorite, at least for the time being.