GeForce NOW has 1 free option (1 hour/day)

GeForce NOW is NVIDIA’s cloud-based game streaming service, delivering real-time gameplay straight from the cloud to your laptop, desktop, Mac, SHIELD TV, or Android device (and more). Connect to your store accounts and stream your own library of games, or play your favorite free-to-play games. With cloud saves for supported games, you can pick up your game where you left off, on any supported device, wherever you are.

GeForce Now (1 hour free every day)

Google Stadia (1 month free trial)

Playstation Now (Over 800 PS4, PS3 and PS2 games on PS4 or Windows PC, 7 days free trial)

Xbox Game Pass (Xbox games first 3 month for 1 euro)

Shadow (Real Cloud Computer $11.99/month)

Blacknut (400 games included with the subscription)

Microsoft Azure (Virtual Machine free for 12 month with limits)

Netboom (One free hour everyday for non-members with limits)

Loudplay (Real Cloud Computer 1 free hour)

NOTE: Not all the games will work with cloud gaming. Also there are more cloud gaming services around not listed here (Facebook Gaming, Amazon Luna, Google Cloud etc etc), i tried to show the correct information but if you want to add or correct, do so using the comments section. The pricing plans showed here could change in future.