I've been trying to find a list of Cloud Gaming services and didn't really find an exhaustive list, so I've created the following.
Let me know if I forgot any or if anything is incorrect. There are some virtual desktops systems and some applications you host yourself to stream from your PC, but I'm excluding those from this list, unless the virtual desktop is specifically for gaming.
Prices listed are the lowest price and services could get more expensive.
BYOG - Bring Your Own Games - this service offers to stream games, but you have to own the game first.
Google Stadia - No monthly fee and just buy the games you want OR $9.99/month for Pro which includes monthly games and higher resolution, but most games you still have to purchase as well - Browser - stadia.google.com
Microsoft X-Cloud - $15/month gets full Xbox Game Pass for PC and Console plus XCloud - Browser or App - www.xbox.com/xcloud
Playstation Now - $9.99/month Not sure all it gets you, but it says hundreds of PS2/3/4 games - App - www.playstation.com/ps-now/
Amazon Luna - $4.99/month - Browser or App - Netflix type service. - www.amazon.com/Luna/
GeForce Now - $4.99/month - Browser or App - BYOG - play.geforcenow.com
Shadow - $29.99/month - App - BYOG - shadow.tech
Vortex - $9.99/month - App - 50 hours/month, Get some games with the service also BYOG - vortex.gg
Parsec - $9.99/month - App - BYOG - parsec.app
Playkey - Pay for time used hourly or in chunks - Browser or App? - BYOG - playkey.net
Netboom - ? - Mobile only atm - ? - www.netboom.com
Blacknut - $15.99/month - App - Netflix type service - www.blacknut.com
Piepacker - Free - Browser - Limited users right now, Retro focused. Not much info, but it looks like they'll have games and you can even upload your own legally acquired games - piepacker.com
Antstream - Free at the moment, but looking to have premium or free via ads - App - Arcade focus streaming service - www.antstream.com
Boosteroid - €4.16/month - Browser - Some games included with service + BYOG - boosteroid.com
FireCloud - £59.95/month - ? - BYOG - www.firepower.cloud/gaming
Maximum Settings - Hourly pricing - ? - BYOG - maximumsettings.com
GameNube - ? - ? - ? - www.gamenube.com
Newcade - No cost because it's decentralized cloud gaming and the content is shared amongst folks - www.newcade.com
nware - 8.99 €/month - App - BYOG? - www.playnware.com
cloud.my.games - Russian and outside my area
Utomik - $6.99/month - App - This one is NOT streamed, but is in comparison to XBox game pass for PC, where you pay a monthly fee and get access to install a lot of games - www.utomik.com
Liquidsky - Appears to be closed
Snoost - Appears to be closed
Playgiga - Appears to be closed - Bought by Facebook
JUMP - ? - ? - Seems to be dead. Website doesn't give hardly any info. CEO and Founder, Anthony Palma, has 2014-2020 on his Linkedin for Jump, so I'm guessing it's dead? - playonjump.com