I work with C# but sadly it's not on the game industries, I work with Asp. Net MVC 3, business applications...

I also know a little of Java, C++ and Python, and recently i'm trying to learn JavaScript, but I am considering JavaScript less and less as a language

Very cool, always interesting to see what backgrounds people come from.

Personally I never cared much about AA but if i had to implement it i would go with a seperable screen space technique. That should give you the best performance stability in relation to the resolution you use. I think the most popular ones are MLAA and the newer SMAA which can be found here: (the source code is also available)
http://www.iryoku.com/smaa/

Maybe the whole technique is a bit too high end but adapting some of the ideas should not be that hard.
And there is FXAA which is quite popular at the moment but i think it should be slower and not as good as the two mentioned above.

http://www.codinghorror.com/blog/2011/12/fast-approximate-anti-aliasing-fxaa.html
This is just a basic comparison and description of some different techniques and at last a thread from January discussing some of the techniques. Theres also the link to the FXAA whitepaper:
http://www.gamedev.net/topic/618958-anti-aliasing-techniques/

qui, some serious stuff there, Thanks for the help. We will go through this and let you know what we add!

We ended up going with option2 and 3 combined. The line thickness of 2 was reduce alot as well... so it is less annoying!

@qui none of those tutorials work for a C# project, sadly! Thank you all for the help. I have +1 all of you, so nice to have good help around here.