Ebbie - 'sound' is a personal thing. What 'sounds' good to one guy may well 'sound' crap to another. Like the others have said, people use finger and/or thumbpicks for various reasons - volume, clarity, a particular tone, or whatever. In my case I used to use them because my nails are very thin and tear easily, and without the 'nail' element on a steel-strung guitar it's difficult to get that nice 'ping' and there's no volume without amplification.

I've used steel and plastic picks on a variety of guitars, from a £100 Yamaha to a £2K Martin and one thing's for sure - a quality guitar played with picks still sounds better than a cheapo.

My current guitars are a Lowden O25 and a Martin J-40 and they sound damn fine with or without picks. However you'll be pleased to know that nowadays I have fibreglass extensions on three nails on my right hand so I don't need the picks any more. The main advantage of falsies is that (a) no more picks dropping off during a song and (b) less pratting about getting them on securely when I stand up to play.

Incidentally, I know a young female blues singer, Emily Druce, who uses metal picks with an old Martin (I think it's an 000-28) and it sounds wonderful. It's a personal thang :-)

Pax,
Johnny