Play free-to-play, with microtransactions games
Free-to-play games (commonly known as F2P) can be freely downloaded, installed and played without paying. Some free-to-play games offer the player the chance to buy items or services for real money (MMORPGs are the perfect example) in an online in-game marketplace. The cost of such items is often very low, hence the "micro" in "microtransactions". These items or services range from increased experience gain items to cosmetic enhancements, additional content, more character slots, etc.
Help Free Games Utopia
Free Games Utopia is a completely free one-person project. If you wish to help, you can donate a few bucks. Thank you!

Wakfu
RPG / MMORPG
Ankama Studio

World of Tanks
shooter / MMOFPS
Wargaming

Legends of Honor
strategy / MMORTS
Good Game Studios

Action Taimanin
RPG
LiLith

Drakor
RPG / MMORPG
Drakor Dev Team

Adventure Quest Worlds
RPG / MMORPG
Artix Entertainment

Goodgame Empire
strategy / MMORTS
Good Game Studios

Popmundo
simulation
ExtraLives AB

Rail Nation
simulation / management
Travian Games

Tentlan
strategy / MMORTS
Lionmoon

Cyberpunk Dreams
RPG
Late Night Games

Mars Tomorrow
strategy / MMORTS
Game Fabrik

Cabals: Card Blitz
card game / collectible card game
Kyy Games

Crossout
action / MMORPG
Targem Games

Skyforge
RPG / MMORPG
Allods Team

Empire Universe 3
strategy / MMORTS
Looki Publishing

Business Tour
strategy / board game
Creobit

Heaven & Hearth
RPG / MMORPG
The Seatribe team

Shadowverse CCG
card game / collectible card game
Cygames

Blush Blush
simulation / dating sim
Sad Panda Studios

Batheo
strategy / MMORTS
Clap Along