kazaa lite is what i use. There are many others my friends use that have smaller databases of music, but they claim they don't get too many broken songs. Good thing about kazaa lite(kazaa lite has no ads, kazaa does) is that it has large collection of older songs, that are ussually not blocked.
I have heard/read though that Itunes (when used with apples downloading website) has the most songs available in its database. These songs are never blocked since you are paying for them.
Finally, if using kazaa lite, i have noticed that a good way to get a new/pop song is to search for the song using the lyrics. For example if the song is Ms. Jackson by outkast, search using the lyrics, 'I never meant to make you cry'. Frequently people will not know the name of a song, and put their own name to a song. But, when the record company goes in and blocks tracks off their CD's, they dont search using the lyrics, just the song name.
