I'll admit I use LimeWire too, but I always try to find the music I want in iTunes first. If the song isn't available from iTunes, I may use LimeWire, but I prefer to buy it. I just don't like buying a whole physical album from a store when I only like one or two songs, and if I can't find them individually from iTunes, I do sometimes stoop to LimeWire. I'll admit I also use LimeWire to get bootleg recordings of live shows. A lot of the music I like is from the 80's so I wasn't able to be at the concerts, but I still like to hear what it would have been like.
I always buy the whole album of my favorite bands, but sometimes there are 'one hit wonders' that I like and I refuse to buy the whole album for one song I like. Maybe more artists and labels will see the value in iTunes and other online digital music stores, and I will one day be able to get anything I want from them...