List of GD songs by bassline

I-IV-V
Waterflame: Jumper
Waterflame: Swirl!

I-V-VI-IV
ForeverBound: Stereo Madness

I-VI-IV-VI-IIIadd2
TheFatRat: Xenogenesis

I-VI-VII-I-VI-VII-IV
EnV: Paladin

i-III-IV
Colbreakz: 2011

i-III-IV-VI
Panda Eyes and Teminite: Highscore
TheFatRat: Time Lapse

i-III-VI-IV
Djjaner: Geometry Dash

i-III-VI-VII
DJ Striden: Level One
DJVI: Can’t Let Go
Nightkilla: Fear Me (briefly after the drop)

i-III-VII-i
ParagonX9: Infinity

i-III-VII-IV
EnV: Pearlescent

i-III-VII-VI
Dex Arson: Unarmed
TMM43: The 7th Day

i-III-viiø-iv
Detious: Golden Haze

i-IV-IV#-V
Nightkilla: Nine Circles (before the drop)

i-IV-V
EnV: Bonus Level
Waterflame: Time Machine

i-iv-ii-i
DJVI: xStep

i-iv-VII-v-VI-iv-VII-V
Nightkilla: 211 (before the drop)

i-V-i-VI-V-i
Waterflame: Final Battle (second part)

i-v-III-IV
EnV: Heaven Rd. 2
RobTop: GD Menu Song

i-v-IV
DJVI: Base After Base

i-v-VII-IV
EDEN, Aaronmusslewhite: XO

i-v-VI7
Nightkilla: Sweet Dreams (also analyzable as i-III-VI7)

i-(v)-VI-III-iv-i-iiø-v
TheLivingTombstone: I Got No Time

i-v-VI-VII
DJVI: Cycles

i-VI
Garlagan: Holography (first part)

i-VI-III-VI-V
DJ-Nate: Center of Existence

i-VI-III-VII
API: Paradise on E Remix
Colbreakz: 10000
Cornandbeans: Midnight
Dimrain47: Duality
Dimrain47: Surface
DJ-Nate: Journey Into Sound
DJ-Nate: Nexus 2
DJ-Nate: The Power (even the beginning, even though it does not sound as such)
DJ Striden: Factor 7
F-777: Dance of the Violins
OcularNebula: Circumnavigating the Glob
TheFatRat: Monody
TheFatRat: Windfall (until the drop)
TMM43: Eurodancer
Waterflame: Electroman Adventures (after the beginning)
Waterflame: Sky Fortress

i-VI-iv-i-III-iv
Bossfight: Milky Ways (many parts)

i-VI-iv-i-iv-i-V
Nightkilla: Jawbreaker (before the drop)

i-VI-V
Nightkilla: Problematic (i is VERY long)
ParagonX9: Chaoz Impact
Shtriga: Armageddon
Shtriga: Massive Discharge
Solkrieg: Phobos
Waterflame: Clutterfunk (sort of)

i-VI-V-III
DJVI: Back on Track

i-VI-VII
BurgeraX: Scorpion (many parts)
Dimrain47: At the Speed of Light (some parts)
Djjaner: Cosmic Dreamer (after the beginning)
DJ-Nate: Theory of Everything (sort of)
Duffany1: Sinusoidal Depleneration (pre-drop)
F-777: Deadlocked (some parts)
F-777: Ludicrous Speed
F-777: Sonic Blaster (after the beginning)
F-777: The 7 Seas (after the beginning)
Gls: Flawless Wings of Yatagarasu (drop)
Goukisan: Guitar vs. Piano v1.2
Kid2Will: Fire Aura
MDK: Fingerbang (augmented x4 after the drop, but still the same chords)
ParagonX9: HyperioxX (slow piano and after)
Rudebrat: The Quick and the Dead (before the drop)
Shinrog: Infertehno
SOCOLLAB: Infertehno 2
TMM43: Sundance
Waterflame: Blast Processing
Waterflame: Final Battle (first part)
Waterflame: Hexagon Force
Waterflame: Lightspeed

i-VI-VII-i
Goukisan: Betrayal of Fate (chorus)
MafiaPineapple: Genesis

i-VI-VII-i-III-iv
Bossfight: Milky Ways (after the beginning)
Bossfight: Milky Ways Redux (after the beginning)
Waterflame: Geometrical Dominator

i-VI-VII-iv
TheFatRat: Unity

i-VI-VII-V
OcularNebula: Stay Inside Me

i-VI-VII-v
OcularNebula: Hurricane Dimension

i-VII-i
Bossfight: Okiba Crackdown

i-VII-v-VII
DJVI: Dry Out

i-VI-VII-i
ParagonX9: Chaoz Fantasy

i-VII-i
Bossfight: Partyt Ar Igang (chorus)

i-VII-VI-iv7-VI-VII-vii#°-ii°
Nightkilla: Fairydust

i-VII-VI-III-VII
Nightkilla: Everlasting

i-VII-VI-V
ParagonX9: Chaoz Airflow

i-VII-VI-V-vi-v-VI-V
Nightkilla: Astronaut 13 Remix

i-VII-VI-i-ii-v-i-VII-VI-III-vi-v-i-v
Steampianist: The Undertaker’s Daughter

i-VII-VI-VII
DJVI: Midnight Sun
Hinkik: Explorers
Hinkik: Skystrike
Xtrullor: Supernova (before the drop; after the drop is i-III-VII-i-VI-V)
Xtrullor: Tria

VI-i-VII-III-VII
DJ-Nate: Evolution of Music

VI-VII-i
Hinkik: Time Leaper

VI-VII-i-III
Aztech + Lockyn: Soulwind
Dex Arson: Level 2 (before the drop)
Hinkik: Ena
Hinkik: Outbreaker

VI-VII-i-v7
Jumper: Purity

VI-VII-iv
Djjaner: Speedbreaker

Irregular:
Dex Arson: Machina
Dimrain47: At the Speed of Light, Forsaken Neon, Operation: Evolution, The Falling Mysts
DJ-Nate: Clubstep: Electrodynamix, Rain, Theory of Everything 2
Duocore: The Furious
Garlagan: Impulse (could be i-III-VI-VII, but not really)
1f1nity: Just about anything
Jomekka: Eighto
ParagonX9: Red 13
SHK: Death Moon
Step: Polargeist
Warak: Reanimation
Waterflame: Endgame
Xtrullor: Anything not listed

Songs that just stick around one chord:
Most dubstep drops
Acid-Notation: Anything
Boom Kitty: Anything
Djjaner: Lullaby RMX
DJ-Nate: Intercept
DJ-Nate: Intercept 2
Duffany1: Bionuclear Anthrax
Dr. Phonics: Everything
Duocore: The Furious
F-777: A New Energy
Garlagan: Holography (second part)
Mr-Jazzman: Iron God Sakupen Hell Yes RMX
Nightkilla: Bass Down Low RMX
ParagonX9: HyperioxX (first part)
ParagonX9: Infiltration
Pegboard Nerds: Gunslinga
Shtriga: Let’s Bounce

Songs which have basslines that I’m too lazy to figure out:
Goukisan: Betrayal of Fear
Lemkuuja: Anything
MafiaPineapple: Exploring Space
RobTop: Random Song 01 (vault soundtrack)

Anything obvious I'm forgetting?