Here’s some from my library. These are all over the spectrum of sub genres of metal, just to be aware.

Living Sacrifice - similar to Slipknot; not been active in over 10 years

Extol - Norwegian black metal; not been active in a few years, just released a short album about 2 years ago

Schaliach - early prog metal; not been active in over 20 years

Azusa - kind of hard to pinpoint a sub genre/similar secular artist; released an album a few years ago

Umpfel - prog metal; released an album about 2 years ago

Sacred Warrior - older thrash type of metal; might be in hiatus after an album release about 10 years ago

Tourniquet - thrash metal similar to Metallica; not been active in about 10 years

Spoken - screamo; released an album a few years ago

Stryper - older 80’s heavy metal, still very active to this day

Tremonti - more like hard rock, maybe a little heavier, similar to bands like Tool, Deftones, Alter Bridge, Sevendust; still active (lead singer is formerly of Creed and Alter Bridge, sort of on the Christian side of things, but has some weird beliefs)

Demon Hunter - hard to pinpoint what subgenre or similar artists, but they are very active and working on releasing an album soon. One of the biggest names in Christian metal over the last 20 years.

War of Ages - kind of in between Demon Hunter and Impending Doom, as far as hardness goes. Still active to this day, re-releasing an album soon

P.O.D. - hard to call them true metal, but they have a few tracks that reach for this level among a mix of reggae and rap. Very active to this day.

Project 86 - kind of hard to say they’re metal too, but some of their more recent stuff has been heavier than previous material. Still active to this day.

The Death in Me - kind of screamo-like genre. Only released one album 10 years ago and disbanded.

Destroy the Runner - a bit harder than Skillet, but similar genre; not been active in a while

Means - similar to Demon Hunter; disbanded 10 years ago but released 2 albums that are really good

Disciple - classic band still going on a few years ago. Similar to Sevendust or Breaking Benjamin, a tad like older Disturbed

Earth Groans - screamo genre; not sure on their active status

East West - classic older band that was a bit harder than hard rock but crossed into metal occasionally on some tracks. Disbanded over 15 years ago but every album was solid

Echo Hollow - thrash metal kind of like Metallica; disbanded over 20 years ago

Precious Death - similar thrash metal to Echo Hollow and Metallica; disbanded over 20 years ago but solid albums

Every Day Life - kind of metal, but more so harder punk and political, very similar to Rage Against the Machine; disbanded over 15 years ago but solid albums

Fleshkiller - an offshoot of Norwegian black metal from some of the minds behind Extol; not sure on active state but released first and only album about 5 years ago

Haste the Day - similar to For Today and similar genres; not sure on active status

HolyName - experimental metal, similar to Impending Doom and Demon Hunter but very different musically. Includes features from both of those plus Brian Head Welch of KoRn. Just started a few years ago and been very active recently

Maylene and the Sons of Disaster - southern metal similar to Hell Yeah. Released some stuff recently, but lead singer has had some health issues, so uncertain. Former lead singer of Underoath over 20 years ago

Remove the Veil - southern metal again, released only one album 15 years ago

Hope for the Dying - similar to For Today; not sure on active status

Becoming the Architype - similar to For Today, not sure on active status

Mantric - similar to bands like Breaking Benjamin, from some of the minds behind Extol again, released something a few years ago

Megadeth - some Christian themes, similar to Metallica since it’s led by former Metallica bassist Dave Mustaine who became a Christian about 20 years ago. Older stuff may be contrary to Christian messages but newer stuff leans into that plus a right political leaning in some ways

Michael Sweet - older thrash-like sound. From lead singer of Stryper, so similar musical vibes here.

Just to name a few that I’ve been familiar with from my personal library of classics