from the ages of 14 to about 18, i played in a rock/metal covers band (stuff like iron maiden, black sabbath, metallica, rhcp, and at my insistence, a strung out song). it was my first band, and it was fun (we even had a bit of a following among our schoolmates and got a decent crowd at the few gigs we did), but it was frustrating as the drummer (whose house we practiced at) wanted to pander to audiences and play well-known stuff only, and was against the idea of writing our own stuff because he got bored while the bass and guitar players were collaborating on riffs etc. basically, band practices weren't the most fun in the world, but gigs really were.
some of us from that band, plus a few others, are getting together this year to learn a bunch of covers and be the drummer's sister's wedding party band, which is cool, as it's a one-off, but i can honestly say i'd never want to play in a covers band again for anything other than one-offs, especially now i know the amazing feeling you get when you go into a practice room with a few ideas and emerge with an actual song.