Reply series is very specific in this aspect but here are some dramas that (at least partially) fulfill your request. Usually, there is not such big ambiguity between which male lead will FL end up with. She loves first male lead and is friends with second male lead but both love her. Also, Reply dramas are ridiculously high quality while harem dramas usually are not that good and are more fan-servicey
Also, I think that harem dramas might be something you are looking for in general?
Anyways, here are my recs (i underlined dramas that are very good and i rec them in general):
Sassy Go Go - very underrated cute school drama. FL and both MLs start as enemies but become soon members of big team (i rec this drama no matter if it fulfills your requirement)
Accidentally In Love - there is only FL, 1ML and 2ML in the group of friends and FL always likes only 1ML
Atashinchi no Danshi - (i dont remember much about the story lol. but i know it is harem drama)
Boys Over Flowers/ Hana Yori Dango/ Meteor Shower (or any other iteration of this story lol)
Flower Boy Ramyun Shop - not my favourite drama but might have the themes you are looking for
Flower Boy Next Door - not my favourite drama but might have the themes you are looking for
Moon Lovers: Scarlet Heart Ryeo - historical drama, mix of cute and political/tragedy. big budget and very good in general
You're Beautiful
To the Beautiful You/Hana Kimi