I personally don't complain when my favorite girl loses as long as the end pairing makes sense, i. e. the minimum amount of explanation, and doesn't come completely out of the blue. That's on the objective level. When it comes to my personal (heavy) bias, I see myself more raging than enjoying. Preferably no forced drama, at all, but that's due to my heavy drama allergy as I have mentioned in various other threads (mostly in the Eroge impression
).
Then again, I also simply dislike love triangles, unless used for comedy. Fortunately, I am much more a VN reader than anime/manga so I have the option to choose the girl (except of enforced playing order and stuff like that) and the genres.
As for Seo?