Freesound.org is an awesome place to download free sounds. I have downloaded a lot of sounds from there that I use in my music projects and track\song compositions. They are great quality and there is a huge selection. Because of this, I felt it was only right to give back by uploading my own sounds to there website. So I have begun contributing to Freesound.org by uploading my field recordings and custom created sfx to their website. So, I have a home that you can visit there now too, another place you can listen to my field recordings and sfx. Visit my profile at Freesound.org.

You can listen to any sound there, but to download the sounds, it will require that you create an account. It is free.