Welcome to the game. Not sure how I could convince you to choose Union of Defiant, but I'm a Union player. Apparently we have the higher population of the 2 but I don't know by how much. Generally people over the whole community are very friendly and you'll find plenty of offers of help. 
If you're in game and need help feel free to send me a global tell to @Dave N Smith. I'm on late most evenings at the moment. 
If you do join Union make sure to hit up on the Global channels we use.
Union Chat - Talk about anything, ask for help, introduce yourself etc.
Sals Badgehunters - This channel is Unions Badgechannel, for hunts, task force making etc.
Union Taskforce - This channel is used to announce Task force (creation), raids etc.
To join any of these channels simply take a look at your UI. You will notice the word "Chat" or any other Tab (you can make a new tab by right clicking on your chat box and selecting "add tab") .
Type in /chan_join "Union Chat" and click enter.
Then right click "chat" and look for something about channels. Then click that choice. You will get a new window divided into two. Left and Right.
On your Left side are the channels that "chat" -tab has active. See if Union chat is on left or right side. If its on the right side, simply move it over to the left, then click accept or Ok.
This way you have Enabled the chat channel (sometimes global channels vanish, with this you know have see how to enable it again)
Repeat as necessary for the other channels.
And as always welcome to the game and hope you enjoy your time with us
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Short Story I did: http://boards.cityofheroes.com/showthread.php?t=228383
DevArt Page: http://tamedragon.deviantart.com/
Hi there, my name is Tiago, i'm 20 and i'm from Portugal
i played this game on issue 11 or 12 on some trial days and since then i had the need to play this game again, so i went crazy and just bought COH: Going Rogue from NCSoft. Since i'm new to the EU servers ( I played on US ), I sure aprecciate some help chosing the server ( Union or Defiant ). Thanks in advance 