Don't you dare, canex! Finnish is awesome.
I'd say Hebrew. If Arabic weren't my native language, I'd say that as well. Easy: I don't like the kh/ch (in hebrew) sound. I could add Dutch to the list, just because of that. And basically every language that uses that sound.
I love that sound! I was just watching a Dutch video, here:
http://www.youtube.com/watch?v=qz8jzVlH8xQBecause I wanted to get an understanding of how the words are said (stfu, I like languages). I really like that sound so long as it isn't... emphasised too harshly.
I do, however, hate Mandarin and Cantonese. I am not a huge fan of Russian either.
Favourites would be French, German, Dutch and the Scandinavian languages.