Interestingly, after a couple dozen lyric searches, I did develop some lyric website loyalty. I'll still come in via search and leave almost immediately after, but I'll actively look for the sites in search results. Criteria include perceived correctness, readability, and not killing my browser (relative to other sites out there).
I also like Songmeanings' comment/user input area, which usually has sensible comments I am occasionally interested in reading.
I tend to click sing365.com links in the search results if I see them. They have a section for user comments which I like to browse. They also manage to load the page up with ads without bothering me. Their bright red "GET A RINGTONE!" text ad actually shows me where the lyrics start.
I also like Songmeanings' comment/user input area, which usually has sensible comments I am occasionally interested in reading.