I speak Icelandic, English, Danish and Swedish fluently.
My Danish and Swedish are pretty good and I understand them completely. One thing that bothers me when I go to Denmark is that if my accent isn't a 100% correct on some word they pretend not to understand me.
I guess I can probably understand Norwegian and speak a bit but I haven't really tried that out to much.
I also speak a bit of Spanish but it's very, very basic.