You should definitely check out
Why, you ask?
Supported games (as of October 2012, each month there is a new game introduced. Even cooler, soon authors of the BGA will allow other member of community to design their own games with BGA Studio!):
4. Race for the Galaxy
5. Can't Stop
6. Stone Age
7. Puerto Rico
12. Uncle Chestnut's Table Gype
18. China Gold
19. In The Year of the Dragon
20. Color Pop
23. United Square
25. The Boss
2. Technology - web based
3. Live play
It's all "live" play as you described it. There is time limit that each player has. After going over that time player might be kicked out of the game. This gives him bad reputation. You can always see how often other players leave the game (frustrating) or take too much time to think about their moves. You can give someone
+1 reputaion or
-1 if you don't recommend playing with that person.
4. Asynchronous play
However if you like, in uncommon situations you might want to host a game without a time limit, and it's also possible (this way you can play a game for a week). So that's for asynchronous play.
And as for tables - the whole system is build around setting a table, players joining it, and accepting table rules. You can join table and be a spectator. You can replay game that took place at certain table and view it from player perspective of your choosing. Great feature for learning what mistakes you made and improving your skills. You can as well watch games between best players.
You asked about active community - oh yes. BGA is being constantly translated by users to 24 languages (including in-game text, instructions and the site itself). I myself did translate a few lines to my native language and improved what already has been translated. Anyone can do it! How about if you play with someone not speaking English or your language? You got translate button next to each sentence they write in the chat - it takes their words directly to google translate!
As i said earlier, there is a reputation system. Something you might be familiar from StackExchange. Works great, and what's important - most players are nice to each other. Want to try a new game? just ask before playing if your opponent is willing to help you get a better understanding of the game.
Feedback from site administrators is also great. Users are reporting found bugs and they are giving suggestion how to improve gameplay or site's interface. That's what BGA Forum is for. I myself have reported bug found in Saboteur, and it got fixed not long after that. You can vote for games to be introduced to the platform. Do you know game called Haggis? You can play with Sean Ross (designer of Haggis) on BGA.
7. Ease of use
I guess you have to find out for yourself. And remember that there is a good chance the site is (at least partially) already translated to your language. And if not - you can help make it so! I found BGA extremely easy to use and very much centered on great gamimg experience. Need help? Go to the BGA Help section.
This is what authors say about themselves:
First, we should say that we are gamers. Real, complete boardgames addicts.
We designed Board Game Arena for players who can't play for real
because of time, geographic or social constraints. We would like to
provide a new game experience with the best of two worlds: video games
and board games.
Although we aim to provide high quality online games, we are still
convinced that the best way to enjoy board games is around a real
table with friends. This is one of the reason we strongly recommend
you to buy physical copies of the games you discover on BGA. The other
reason is simple to understand: each game sale is also a revenue for
an author and an editor (... we've come full circle).