And optionally, why, their best song, a description of them, etc.

h4. 5. Koven
Genre: Dubstep
Description: A DJ + an amazing female vocalist with very powerful melodic drops.
My Favorite Song: <<www.youtube.com/watch?v=3d8B5OM5RsI|Revenant>> (technically it's a collaboration but it very much represents their style)

h4. 4. Marilyn Manson
Genre: Metal / Rock / Industrial
Description: A band notorious for its dark and emotional lyrics and coverage of many different types of rock/metal.
My Favorite Song: <<www.youtube.com/watch?v=rKpixJvzsBE|Disassociative>>

h4. 3. Infected Mushroom
Genre: Trance (ayyy) / Dubstep / Metal
Description: An electronic duo that sticks to mostly trance, but has many songs that are a fusion of trance with metal or dubstep.
My Favorite Song: <<www.youtube.com/watch?v=s2uZXvacw5Y|Heavyweight>>

h4. 2. Pendulum
Genre: Drum & Bass / Rock / Dubstep
Description: A large group of australians that have gone into almost every style of electronic music possible. They're a great band to listen to as a beginner course in electronic music.
My Favorite Song: <<www.youtube.com/watch?v=dbQFh0IeZdg|Encoder>>

h4. 1. System of a Down
Genre: Metal / Rock
Description: I attribute a large part of my personality to this band. They can be crazy, serious, insightful, emotional, epic, and I probably would have never cared about politics if it weren't for them. Besides that, they have a very distinct sound overall, both in the way they play their instruments and in the way their vocals are delivered.
My Favorite Song: <<www.youtube.com/watch?v=MlcJQYON2Go|Chop Suey>> (could change between Chop Suey, Question!, Streamline, Highway Song, or The Metro on any day of the week)

Hmm, in no particular order...Koji Kondo, Nobou Uematsu, Kazumi Totaka, Brentalfloss, and Smooth McGroove. Kinda covers everything I care about.

For me...

Metallica
Pantera
Mudvayne
Machine Head
and Demon Hunter

So, I guess this is just the top 5 bands/artists that you like the most? Because, for some reason, when I read "top 5 musicians", I was thinking like your top 5 influential musicians.

Yeah. The wording for this kind of thing is tricky because either you say band and you imply that it's a group of people when it could just be one or you say musical artist and it could be more than one person.

Everyone loses, so I just used what I think the best way to say it is. "Musician" rolls off the tongue the best to me.

Yes, I know there are two 4s.

h4. 5. Nagi Yanagi/Supercell
Description: Nagi Yanagi isn't affiliated with Supercell, but two of my favorite songs from her are with them. Her voice rivals that of senya's, though. She'd be up there with her if I'd listened to more of her songs.
My Favorite Songs: <<www.youtube.com/watch?v=IvjPSEB-AqY|Yuki Toki>> Nagi Yanagi only.
<<www.youtube.com/watch?v=rS91FpbGuF8|Utakata Hanabi>> This and Yuki Toki are my favorites from Nagi Yanagi.
<<www.youtube.com/watch?v=ZtKoRJcdRBU|Feel so Good>>
<<www.amazon.com/Black-Rock-Shooter-Feat-Hatsune/dp/B005331P8U|Black Rock Shooter>> Amazon link, couldn't find any free links. Supercell only. This is one of my favorite songs of all time. It's been the most played song on my phone for years, with 14 days of total play time over 4142 plays.

h4. 4. Shibayan Records
Description: Shibayan is pretty prolific, and their music is awesome too. They mix up the songs well without losing the melody. I think they usually do electronic music, but their traditional stuff is great too.
My Favorite Songs: <<www.youtube.com/watch?v=_-_h2vQyzJY|Fall in the Dark>> Rumia's theme. It seems to do pretty well in arrangements.
<<www.youtube.com/watch?v=Kyrh9YclT3w|Close to your Mind>> Satori's theme, probably my favorite Touhou character and theme. Bossa Nova.

h4. 4. Nekomata Master
Description: I don't really know how to describe Nekomata Master's music. It's just good.
My Favorite Songs: <<www.youtube.com/watch?v=n51F7DeUQGg|Most of the Sayonara Sekai Album.>>

h4. 3. Floating Cloud
Genre: Folk
Description: Floating Cloud makes folk arrangements of Touhou music, and they're damn good at it too.
My Favorite Songs: <<www.youtube.com/watch?v=ygSxQY34SUg|Flower Village>>
<<www.youtube.com/watch?v=ivZY4Cvcshc|Riverflow of Kappa>>
<<www.youtube.com/watch?v=NUDNSUhRA2I|紅楼 (Arrangement of Crimson Belvedere)>>

h4. 2. Mitchie M
Description: Mitchie M makes music using Vocaloids that have been edited to sound much more human-like. It's cheerful and upbeat, and he has amazing animations to go with them.
My Favorite Songs: <<www.youtube.com/watch?v=zkLJoFp2UAE|Ai Dee>>
<<www.youtube.com/watch?v=KmvydnVTriE|Freely Tomorrow>>
<<www.youtube.com/watch?v=l69v6SVoE9k|News 39>>
<<www.youtube.com/watch?v=8kX5_69sO8Q|Burenai ai de>>
These are coincidentally ordered by date, and you can hear her voice get better across them. The first two have 2D animations, while the latter two use 3D models.

h4. 1. Yuuhei Satellite/Catharsis
Description: Yuuhei Satellite's position here is almost entirely down to one of their vocalists, senya. I love her singing and listen to this circle's music for it.
My Favorite Songs: <<www.youtube.com/watch?v=zKR-wKadW7c|Nihilistic Kagura>> Theme of one of my favorite characters, Alice.
<<www.youtube.com/watch?v=jTgYtkc4kgg|Opposite World>>
<<www.youtube.com/watch?v=xyDPSw6AM7c|Though the Scent Lingers, the Flower Scattered>> This is probably better known as the OP of the Touhou animation Memories of Phantasm.
<<www.youtube.com/watch?v=sOnaWf1cXsM|Tsuki ni Murakumo, Hana ni Kaze>>
<<www.youtube.com/watch?v=NdBVOTNSjxQ|Sakuretsu Irony>>
<<www.youtube.com/watch?v=oSkVhqJjnpw|揺れる恋は波の如く>>
<<www.youtube.com/watch?v=eVvNj54hOFc|暁の水平線に>>

h4. Honorable Mentions
h6. Girls und Panzer
I love the historical wartime songs from this anime.
<<www.youtube.com/watch?v=t8bEZcw3-wM|Säkkijärven Polkka>> More reason for me to love a country I've never been to.
<<www.youtube.com/watch?v=9wZlbHVU7bU|Battle Hymn of the Republic>>
<<www.youtube.com/watch?v=C5Az984gVdU|Katyusha>>
I love these two songs.
<<www.youtube.com/watch?v=zg-C8A4VvL4|US Field Artillery March>>
<<www.youtube.com/watch?v=AvU8LaE0-xw|The British Grenadiers>>
<<www.youtube.com/watch?v=zUi1A2zuHdk|Panzerlied>>
<<www.youtube.com/watch?v=PVqjhyRxH3M|When Johnny Comes Marching Home>>
h6. Caravan Palace
A French group that makes some pretty awesome music. They also have some pretty awesome videos to go with their music.
<<www.youtube.com/watch?v=fBGSJ3sbivI|Rock it for Me>> Dancing robot. That is all.
<<www.youtube.com/watch?v=9BoaOsvZmpw|Jolie Coquine>>
<<www.youtube.com/watch?v=wGegubqsWiQ|Dragons>>
h6. Reol
Utaite who covers a lot of vocaloid songs. Good voice.
<<www.youtube.com/watch?v=p-o_bMkzOW0|LUVORATORRRRRY!>>
h6. 96neko (kuroneko)
Another Utaite who also covers a lot of songs. More masculine voice.
<<www.youtube.com/watch?v=_XTCh6qBy5s|Online Game Addics Sprechchor>>
<<www.youtube.com/watch?v=0jV9bB-Q7JU|Jingle Bells>> This one features two other utaites, VIPTenchou and Kogeinu. It's quite amusing since 96neko sounds quite boyish, while VIPTenchou sounds quite girlish.
h6. Grand Thaw
Makes some great music that I like to come back to sometimes. I don't listen often, but it's always good when I do.
<<www.youtube.com/watch?v=vfQWdjPikAs|Grad Erlija>>
<<www.youtube.com/watch?v=AnTIq5t7xEs|Äventyr>>
h6. TAMUSIC
Makes some nice music, usually piano/violin related. Sometimes does vocal music.
<<www.youtube.com/watch?v=hQuYz6z7GJQ|Rigid Paradise>>

Jackson Browne
Coheed & Cambria
MC Frontalot
Lin-Manuel Miranda
Yasunori Mitsuda

That about sums it up.

Kendrick Lamar: His raps often mean something deeper, such as talking about unification despite our diffences, or his struggles through becoming an aspiring rap artist in the ghetto and his goal to carry on the style of rap and hip hop that Tupac took with him when he died

Hideki Naganuma: Famous for his work on Jet Set Radio, hes also done tracks for Panty and Stocking and Airgear. His songs are always upbeat and energetic, and are what many people remember Jet Set Radio for

Lazerhawk: Bringing back the 80s, Lazerhawk makes synthwave music, which aims to bringback the hairspray neon colored 80s back in its musical essence with its synth guitars and sounds

Peturbator: If youve played hotline miami, you know him. He makes incredibly good electronic music, ranging from something chill to something aggressive and upbeat.

Daft Punk: No explanation really needed :P

1: Starbomb
2: Weird Al
3: NSP
4: Brentalfloss
5: Yogscast

5: Yoko Shimomura: She probably has made at least 1/4th of my favorite music, mostly from Kingdom Hearts
4: Murray Gold: Seriously, he made the 2005 version of the doctor who theme (the best one IMO)
3: Martin O'Donnell: I literally cant explain how amazing his music is. Too bad Activision shut down Music of the Spheres (One of the reason I really hate Activision)
2: Kevin MacLeod: This guy has made at least 2k music tracks, you have to like at least one of them.
1: Alexander Brandon: Has mad my most favorite tracks so far, and has done some work for some big video games recently.

In no particular order...

ZUN
Composer of the tracks from all main-series Touhou games. He also programs them. And draws the artwork for them. He's a pretty awesome guy.
Toby Fox
I liked Toby before he was cool. I mean, he was always cool, but due to being a Homestuck fan, I've known about his work way before he made Undertale.
NoteBlock
NoteBlock likes to remix tracks from various video games, and I love his style, since he often throws music from other games into his remixes
LOrb Sheddy
Another VGM remixer, LOrb Sheddy (Life Orb Shedinja, a Pokemon joke)'s style is also really really good.
Yuki Kajiura
Composer of a lot of anime soundtracks, including SAO's music, which is all amazing.

Dire Straits, Queen, 10cc, Metallica & Talking Heads for classics.

Absolutely agree with Perturbator, Daft Punk & Pendulum from what other peeps have mentioned. Metric are more mainstream but have made a couple of solid albums. I need to listen to more Man'oWar but the Gods of War album is excellent.