Streambeats – Harris Heller - https://www.streambeats.com/

BackingTrack Music – EposVox - https://backingtrack.gg/

Twitch Panel Maker & Templates - https://nerdordie.com/resources/free-resources/customizable-twitch-panels/

Stream Elements - https://streamelements.com/

These provide various enhancements to not just streamers but viewers:

https://betterttv.com/ | https://www.frankerfacez.com/ | https://www.better-points.com/

OBS Master Class Guide by Epos Vox - https://www.youtube.com/playlist?list=PLzo7l8HTJNK-IKzM_zDicTd2u20Ab2pAl

OBS Studio: https://obsproject.com/

Stream Labs OBS: https://streamlabs.com/

OBS.Ninja - Wireless Camera Tool - https://vdo.ninja/

Discord Streamkit Overlay - https://streamkit.discord.com/overlay

Giveaways Tool (and more) - http://www.lachhhtools.com/

Stream Idea Generator (great for impromptu topics) - https://livestreamideas.com/

Discord Reactive Images (great for static image instead of cam use) - https://discord-reactive-images.fugi.tech/

Media Triggers (chat based event triggers) - https://overlays.thefyrewire.com/widgets/triggerfyre/

Shortcut: https://shotcut.org/