Here is the collection I use the most; feel free to download the .zip file. I took the liberty of giving the IES files artist friendly names. Using IES profiles to scatter indirect light energy into a scene gives a certain legitimacy to the render; even if the profile isn't used for light scatter effects directly. You can accomplish indirect scatter by setting up photon only lights with an IES profiles.
Derek Jenson Blog
My website serves to archive experiments, document projects, share techniques, and motivate further exploration & artistry in 3d space.