My first time playing Stardew, I fell head over heels for Leah
I actually ended up marrying her again in another save file before trying other routes.
I actually paid little attention to the social aspect of the game until my third or fourth file, but after seeing the heart events for the bachelor/ettes, I grew to like characters I didn't think about before ^u^ My next love was Shane, who was actually a character I previously didn't care for much at all!
Other favorites are Sam, Haley, and Alex~ I'll get to them all eventually :P (To answer the oppostie, I don't see myself marrying Harvey, Sebastian, Maru, or Elliott anytime soon...)