Chordie, as in http://www.Chordie.com/ -- guitar tabs, guitar chords and lyrics.
One of my favorite things about Chordie versus any other tab/lyrics site is randomness. They allow users to make their own collection of songbooks. Those songbooks, should the user choose, are available to be used and perused by the general public. That's what I do during my basement sessions: click on the 'Public songbooks' and experiment away with songs from a multitude of generations.
For example, writing this, I just emerged from the basement where I toyed around with the following songs:
"Ain't No Sunshine" by Bill Withers
"Name" by the Goo Goo Dolls
"Drift Away" by Dobie Gray
"That's Amore" by Dean Martin
Maybe "Ain't No Sunshine" and "Drift Away" overlap in style a little bit, but "Name" and "That's Amore" ... not so much.
The fun I have poking around Chordie also highlights one of my biggest playing/practicing bad habits: not sticking to and learning one song thoroughly from end to end. I bore quickly and Chordie makes it possible for me to find a new song.
If you're a player, check out Chordie and have some fun.