.com are what i always try for, .net I actually only have one site right now with that, but if you look at any google search they rank just fine... .org do well, but the only ones I've ever seen don't have any kind of ads or selling going on, I'm not sure if that is just coincidence or a real pattern... But, I think that may be something Big G is looking at in the .org area...
For .info and others, I really think they are dogs that should be avoided right now; anyways, I have yet to find a .info that ranked for any keyword I was looking at.
That may be because its new, but I think it may be because G knows they are new and therefore are not a proven commodity in the mind of the consumer/user also, so they are not ranking them as high as they might if they where .com .net or .org sites.
But these are just my own observations...