I always absolutely loved Latias, and she's still one of my favorite Pokemon - maybe even my #1!
Part of that preference is aesthetic, as I love her design and her red and white color scheme. Another part of my preference is probably owed to the fact that I played Sapphire before Ruby, and thus whichever Eon I encountered first would take precedence. Like the third generation as a whole, the Eons to me represent exploration and the vastness of the world, which I love - Latias seems to represent it more for me solely because I saw her first.
Another facet to that, though, is using them; what Latias lacks in offensive capability she makes up for in diversity of abilities. To use her properly, you have to really think about how you're using her moves and capabilities and how she fits on a team. Her lack of offensive raw power means that using her requires a more intellectual and nuanced approach, and I kind of like that.
Catching each was always a challenge, but I did it, and I made sure to choose Latias in Emerald most of the time.