there was a lot of good B-sides this year that it's unfair to just mention one so here are the rest of my top ones:
Seulgi - Better Dayz
NMIXX - High Horse & Reality Hurts
ARTMS - Goddess
VIVIZ's UMJI - Love Language
TXT's Yeonjun - Ghost Girl
ENHYPEN - Helium & Flashover
and my 2025:
SOTY: NMIXX - Blue Valentine
A(Artist)OTY: NMIXX (same here they absolutely owned 2025 imo)
A(Album)OTY: Cerulean Verge by Wendy (nmixx's blue valentine was a very close second)
B(B-side)OTY: LE SSERAFIM - Ash
also my 2024:
SOTY: ARTMS - Virtual Angel
A(Artist)OTY: aespa (2024 was their year they owned it)
A(Album)OTY: Metamorphic by STAYC
B(B-side)OTY: VIVIZ - Cliché