Top 20 free online games
1. Tycoon Online
Tycoon Online is a web based business game. 
Tycoon Online aims to create a virtual business environment where each player owns and run his own company. At the same time the system requirements shall be low and the prerequisite the same for every player.
2. Bushtarion
Bushtarion is a free web-based strategy game in which you get to head up your own gardening company, and ally or war with other companies.Research new technologies and gain access to a massive array of units, ranging from petrol bombers, to terrorists, to snipers, to assassins, to apaches, to androids, to huge robotic tyrannosaurs.
Choose from one of five finely balanced technology routes - protestors, thugs, military, robotics or special operations, each with their own unique play-style and set of tactics.Be defensive and develop immensely powerful immobile units like automated sentry turrets and bunkers, defending your land from would-be attackers, or be an all out offensive player and go rampaging through other players land, killing & bribing their staff, and stealing their land for your own crops.
3. Eternal Lands
Eternal Lands is a free MMORPG (massive multiplay online role playing game). There are 9 skills, total character development freedom, many quests, religion, a lot of NPCs, animals and monsters. If you are a PKer, you can fight other PKers in special maps. If you are not a PKer, then you can stay on the non PK maps, where you don't have to worry about being attacked by other players.
4. Neveron
Neveron is free strategic online game. Build your empire through near-limitless possibilities from military conquest to peaceful economic growth. Join thousands of players competing for dominance in a free game of intense tactics, cunning politics, and futuristic warfare.
5. TEQ
Terra Est Quaestuosa is a free strategic webgame that is played by thousands of players. Build up your country, join a team and acquire the most networth.
6. Soldat
Soldat is a unique side-view multiplayer action game. It takes the best from games like Liero, Worms, Quake and Counter-Strike and gives you fast action gameplay with tons of blood and flesh. Soldiers fight against each other on 2D battle arenas using a deadly military arsenal. This is what multiplayer was invented for.
7. Cantr II
Cantr II is an online role-playing game , in which a large number of players play an even larger number of characters who all together form different societies all over our virtual world. Societies exist in different languages, whereby all language groups play in the same virtual world.
Playing always from the perspective of each individual character , you can try to play the worlds most famous politician, most feared criminal, most cunning military commander, most wealthy entrepreneur, or most beloved village idiot. Any role you can imagine you can play in this game and the challenge is in playing it consistently, and in achieving the goals you set for your characters individually.
8. Project Entropia
Project Entropia is a massive virtual universe with a real cash economy .Together with people from all over the globe you experience adventure, you form societies, and you are a part in the creation of a brand new world.While on the planet Calypso you use the PED currency to invest in your personal development. The assets you acquire can be exchanged back into real world funds.
9. Injustice
The goal of the game is to become the most powerful person on the site - how you go about doing that is completely up to you.The game is all about experience - and choosing your own path! Everything you do will add to your character's experience points and eventually help you grow.There is 7 injustice paths: Gangster, Pollice Office, Armed Forces, Funeral Services, Hospital Staff, Banking and Law.
10. WWII - War of Supremacy
World War II - War of Supremacy is free online game played in browser.You can chose from six nationalities: Germany, Italy, Japan, Great Britain, United States and Russia.Build you army and crush your enemies or discover nuclear weapon and nuked them all.
11. 1000 AD
1000 AD game is a turn based game. You only need a web browser to play it.
10 civilizations to chose from each with special units like samurai, berserker, paladin or shaman. The most important resource of the game is land. There are 3 types of land: mountains, forest and plains. Each building can only be built on one of those. You can send your armies to attack other empires. There are 3 types of attacks: army, catapult and thief.
12. Tibia
Tibia is a free fantasy massive multiplayer online role playing game (MMORPG). Take the role of a valorous adventurer and explore a mysterious world filled with magic and bravery! Meet up with people from all over the world to live through a whole new game experience!
13. Republic Online
Republic Online is a large online game based on countries and citizens. When you sign up, you will become the citizen of a country. You will have to earn money, pay taxes, get married. This will be your chance to meet other people playing the game and talk, marry and fall in love with them. You can earn money either by having a profession (of which there are a lot, from builder to professional thief), or you run a farm and live off their harvest. If you are a very knowledgeable person, you can always enter the Republic-Online quiz, where you can win money by answering 3 questions.
14. Nuke Zone
NukeZone is a strategic text-based game played on the web directly through your browser.Featuring real-time team-orientated gaming, NukeZone can also be played as an individual. Build your province into an international Nuclear power and destroy all opposition along the way with your army of air, sea and ground forces.
15. Runescape
Runescape is a massive multiplayer adventure, with monsters to kill, quests to complete, and treasure to win. You control your own character who will improve and become more powerful the more you play.
16. Wulfram II
Wulfram is a multiplayer, action-strategy game, that allows up to 64 players per server. Control over the hovertank and destroy enemy base. The player is part of a team, and can help that team win in many different ways. Without going into excruciating detail, the players can help build new bases, help place strategic elements that allow spaceships to maneuver, help your frontline tanks by going in with a medic unit and repairing their damage on the battlefield, help the team by rushing enemy bases all alone, or be part of a large group of frontline tanks that battle it out over the territory at hand.
17. Sky Lords
SkyLords is a real-time, browser based, online, multiplayer strategy game (MMOG), which includes many features such as diplomacy, trading, piracy, espionage, space battles, custom spaceship model designing, round bonuses and clan warfare.
18. America's Army
America's Army is one of the five most popular PC action games played online. It provides players authentic military experience , from exploring the development of Soldiers in individual and collective training to their deployment in simulated missions in the War on Terror.
19. Master of Medival Times
Your objective in MoMT is to gain exp, build and train your army, Attack and defeat your enemies, move up to higher levels, join or form an alliance (if you not in an alliance you will find it impossible in higher levels), make enemies and allies and become the strongest player to become The Master of Medieval Times.
20. Sim Country
Simcountry is your opportunity to be the President of a country or the Chief Executive in a group of huge corporations.You play with and compete against thousands of players worldwide.
It can be played in a simple way but is also allows you to become a very sophisticated user, involved in many interesting economic and financial decisions. You may choose to manage all details or leave some to an automated process.