Well... Super Junior was my first bias group. I discovered them in 2012 though.
I don't stan them anymore, but sometimes I listen to their songs. Especially old songs.
It is hard for me to pick a favourite.
But one of them is "Daydream"
But they have a lot of songs that I really like.
I think most of the songs that I like by them are ballad, R&B etc...
I tend to also like a lo f Super Junior-KRY songs. (perhaps because Kyuhyun was my bias)
And also, some songs that make me feel nostalgic.
Other favourite songs:
You Are he One (maybe "outdated", but I find it cue and nostalgic)
Don't Don
Sapphire Blue
Song For You
Happiness (I prefer that version over H.O.T's version)
Heartquake
What If
U (well... when I first heard this song, it gave me Cheetah Girls vibes)
In My Dream
Shake It Up
All My Heart
No Other
My Love, My Kiss, My Heart (Kyuhyun's "울려대는~~" part gives me goosebumps every time)
Opera
Good Luck (I find this song kinda cute)
Evanesce
Don't Go Away (my favourite Super Junior-T song)
Kimi Ga Naitara (I remember having a phase where I listened to that song a lot)