I'm having fun with it.
The will to neither strive nor cry,
The power to feel with others give.
Calm, calm me more; nor let me die
Before I have begun to live.

-Matthew Arnold

Arguments are to be avoided; they are always vulgar and often convincing.
I'll try to interest you with an advertisment text of one game. How good it is - judge by yourself.

Legends of Metaplane is a brand new Browser-Based MMORPG that combines many different game elements making it extremely vast in amout of features and possibilities.
The game is currently in beta stage of development and grows constantly, so every person willing to take part in testing is warmly welcome.
Legends of Metaplane includes the following features:
- 4 playable races with unique abilities and spells
- 4 class paths and 12 playable classes (that are chosen by characters at 6th level)
- a very big and still growing world
- explicit quest system (6 types of quests: exploration, 3 types of item acquisition quests, assassination, converse)
- quest-based storyline and infinite amount of randomly generated quests.
- traditional character equipping and customisation features of RPG
- easy to understand and exciting PvP (Player vs. Player) combats that consist of asynchronous rounds creating the atmosphere of a real-time battle.
- mass PvP and PvE (Player vs. Environment / AI) battles with up to 50 players from each side allowed simultaneously.
- instances (dungeons replicated for every adventuring party) oriented on raid groups from 5 till 50 players with lots of enemies and "bosses" to challenge.
- hundrends of items of different kind: from food, drinks, mushrooms and herbs till epic weapons and armor sets
- a very complex but still easy to understand economic system with possibility to build, upgrade and customise your own houses, shops, farms or workshops of any type: from mills and cattle farms till alchemist's laboratories and magical smitheries. Yes, you can leave the Role-Playing and "violent" parts and dedicate your character's life to becoming a king of trades.
- lots of spells available for use at any time (racial spells, spells granted by your class, specialization, magical items or by one of many other means)
- 9 skills and professions to specialize at.
- compatability with virtually all browsers (IE, Opera, FireFox, Google Chrome and others). The game is perfectly accessible from mobile phones and even iPods.
- many other features are being implemented and added every day.

We will be very glad to see you among the first of game world's inhabitants! Every player counts!

Join "Legends of Metaplane" at http://legends.metaplane.net
find yourself a buddy and play slimeathlete.com

I wasted half an hour on that the other day with my brother
www.adultswim.com has a couple alright ones.

I mostly play tower defense games in my browser though.
None are more hopelessly enslaved than those who falsely believe they are free.
Heli Attack 2 is amazingly addictive. I got about third in the whole world once, I then proceeded to beat this score the next time, but the highscores wouldn't load. I was gutted.