Tamron 28-75 2.8
Agreed, this is a great lens for someone who has switched to full frame, but doesn't have the budget for L lenses. I keep mine around for backup.
I also have a friend who shoots lots and lots of people pix with this lens on a 7D. Its a nice portrait lens on a crop body.
This was excellent when I had it and used it on my 40D (now sold). For my 7D (which I normally use only with long lenses) I have a Tamron 17-50mm F/2,8 and it's absolutely fabulous.