NOTICE: PLEASE READ THIS before commenting about missing themes or anything.

Please do not ask me about themes like the Underground music from games like Super Mario Bros. 2 or Super Mario World. I am aware those exist. I excluded them for the sake of consistency, as I only wanted this compilation to contain themes that actually remix the original Underground theme from SMB.
I tried my best to make sure I did not miss a single theme out of that, but if you somehow still find an Underground remix in a Mario game, feel free to comment it.

This is a complete & fully comprehensive collection of just about every single remix of the original Underground theme from Super Mario Bros. for the NES in the entire Mario series (and spin-offs). I’ve noticed that all other such compilations on YouTube are either incomplete or obsolete, so I decided to make my own, which should not lack any song.

List of songs and timestamps:
0:00 – 01 – Super Mario Bros. (1985) – Underground
0:51 – 02 – Super Mario Bros. Special (NEC PC-88/Sharp X1 game) (1985/1986/1987)
1:33 – 03 – Super Mario Bros. 3 (1988) – Underground
2:31 – 04 – Super Mario All Stars (1993) – Underworld
3:15 – 05 – Super Mario RPG (1996) – From inside the Earthen Pipe
4:25 – 06 – Super Mario 64 (1996) – Cave Dungeon
8:12 – 07 – Mario Party (1998) – The Room Underground
8:54 – 08 – Paper Mario (2000) – Underground Pipes
10:06 – 09 – Luigi’s Mansion (2001) – Staff Credits (excerpt)
10:24 – 10 – Super Mario Sunshine (2002) – Underground
11:03 – 11 – Super Mario Sunshine (2002) – Shadow Mario
11:51 – 12 – Super Mario Sunshine (2002) – Delfino Airstrip
14:10 – 13 – Mario & Luigi: Superstar Saga (2003) – Underground Tunnel
15:25 – 14 – Super Mario 64 DS (2004) and New Super Mario Bros (2005) – Minigame Theme (Whack-a-monty, Coincentration and others)
16:25 – 15 – Mario & Luigi: Partners in Time (2005) – Peach’s Castle Dungeon
18:37 – 16 – Mario Party Advance (2005) – Minigame Theme 7
19:40 – 17 – Mario vs. Donkey Kong 2: March of the Minis (2005) – Magnet Mania
20:53 – 18 – New Super Mario Bros. (2005) – Underground
23:00 – 19 – New Super Mario Bros. (2005) – Staff Credits (excerpt)
23:17 – 20 – Super Paper Mario (2007) – Nostalgic Underground
24:27 – 21 – Super Mario Galaxy (2007) – Space Athletic
25:43 – 22 – Super Mario Galaxy (2007) – Cosmic Comet
26:42 – 23 – Mario Party DS (2007) – Boogie Beam minigame jingle
26:50 – 24 – Super Smash Bros. Brawl (2008) – Underground Theme
28:31 – 25 – New Super Mario Bros. Wii (2009) – Underground Sewers (reused in New Super Mario Bros. 2 in 2012)
30:44 – 26 – New Super Mario Bros. Wii (2009) – Underground Volcano
32:25 – 27 – Super Mario Galaxy 2 (2010) – Beat Block Galaxy
33:22 – 28 – Mario vs. Donkey Kong: Mini-Land Mayhem! (2010) – Secret Storage
34:48 – 29 – Super Mario 3D Land (2011) – Underground Cave
36:59 – 30 – Mario Party 9 (2012) – Choice Challenge
38:25 – 31 – Paper Mario: Sticker Star (2012) – Underground Cave Connection
40:26 – 32 – Mario & Sonic at the London 2012 Olympic Games (2012) – Underground (SMB) remix
42:46 – 33 – New Super Mario Bros. U (2012) – Underground
43:53 – 34 – Newer Super Mario Bros. Wii (fangame) (2013) – Underground (SMB)
45:07 – 35 – Super Mario 3D World (2013) – Underground Cave
46:24 – 36 – Super Smash Bros. for 3DS & Wii U (2014) – Underground Theme
47:01 – 37 – Mario vs. Donkey Kong: Tipping Stars (2015) – Soundtrack 8
48:21 – 38 – Mario vs. Donkey Kong: Tipping Stars – Soundtrack 9
49:52 – 39 – Mario vs. Donkey Kong: Tipping Stars – Soundtrack 10
51:04 – 40 – Mario Party 10 (2015) – Going Deep
52:03 – 41 – Mario Kart 8 (DLC 2) (2015) – Super Bell Subway – Underground
54:37 – 42 – Super Mario Maker (2015) – SMB Underground (My personal favourite, see my full top 5 below)
57:40 – 43 – Mario & Luigi: Paper Jam (2016) – Doop Doop Dunes (Underground)
1:00:02 – 44 – Paper Mario: Color Splash (2016) – Indigo Underground
1:01:59 – 45 – Paper Mario: Color Splash (2016) – Mustard Underground
1:04:08 – 46 – Paper Mario: Color Splash (2016) – SMB3 Underground (Perspective)
1:04:59 – 47 – Super Mario Run (2016) – Underground Theme
1:06:23 – 48 – Mario & Luigi: Superstar Saga + Bowser’s Minions (2017) – Underground
1:07:38 – 49 – Super Mario Odyssey (2017) – Subterranean 1
1:10:11 – 50 – Super Mario Odyssey (2017) – Subterranean 1 (8-Bit)
1:13:31 – 51 – Super Mario Odyssey (2017) – Subterranean2
1:16:24 – 52 – Newer Super Mario Bros. DS (fangame) (2017) – Underground

My personal favourites:
1. 54:37 – 42 – Super Mario Maker (2015) – SMB
2. 32:25 – 27 – Super Mario Galaxy 2 (2010) – Beat Block Galaxy
3. 4:25 – 06 – Super Mario 64 (1996) – Cave Dungeon
4. 38:25 – 31 – Paper Mario: Sticker Star (2012) – Underground Cave Connection
5. 24:27 – 21 – Super Mario Galaxy (2007) – Space Athletic

This compilation would not have been possible in this form without the help of my good friend BenjuKatchowee, who helped me find a handful of the lesser-known tracks in this compilation.