Yes we all know about the big players: Zoom, Google Meet, Skype, Slack, Webex, Join.me, GotoMeeting (now owned by LogMeIn). And we know about the personal apps: Facetime, WhatsApp, WeChat, HouseParty, and even Instagram Live, YouTube Live. Also some chat adjacent players like GroupMe and Discord

What else is out there if those don't make you feel comfortable or meet your needs. First up the underdogs:

Jitsi.org - develop and deploy full-featured video conferencing
Free open-source video conferencing for web & mobile. Make a call, launch on your own servers in minutes, integrate into your app, or develop something new
Jitsi
Video Meetings, Video Conferencing and Screen Sharing
Easy video meetings with no login or downloads. Video conferencing with screen sharing, recording and much more.
Whereby
you may remember whereby as their previous brand appear.in
Talky
Group video chat and screen sharing. From &yet
RemoteHQ - Collaboration, simplified.
Real-time remote collaboration, all in your browser.
Collaboration, simplified.

Probably the first two in the free video conference space i used "seriously" in business... seriously in quotes because i never saw any business pay for them and somehow they seem to have moved to the less favored status for reasons i don't understand.

Web Conferencing and Online Meetings | UberConference
With robust features and an intuitive and user-friendly interface, UberConference is an amazing software for web conferencing and online meetings.
Features Pricing Customers More Mobile International Integrations Jobs FAQ Legal
Free Conference Calling Services | FreeConference.com
FreeConference.com offers free conference call solutions for you to connect through telephone or online with your customers, relatives or colleagues anywhere.
PuffinFreeConference.com

and the only 4k stream one i know of

Lifesize: Video Conferencing System & Meeting Room Solutions
Lifesize is a purpose-built video conferencing solution for the modern business. Try our industry-leading app for free! See why Lifesize is used by organizations around the world to connect anyone, anywhere, on any device or in any meeting room.
LifesizeLifesize

the only one i know focusing on sound quality by adding Dolby Voice

Blue Jeans Network
Online video conferencing service that is affordable, interoperable (multi-vendor, multi-device), easy-to-use, scalable (multi-party) and secure. Free 30-day trial.
– MANUEL ALACANTARA, INTUIT, TRUSTRADIUSBlue Jeans Network

a special mention to HighFive, not exactly the same as the rest here but probably the best "in room" join conference room to remote conference room one i have used.