Phenom II X3 715
The fastest 95W and AM2+ Phenom I could find. A couple of site have them used for around $100.
EDIT:
For the record, I have a backup tower that has that exact same chipset and I had my Phenom II X6 1090t AM3 in there for a few weeks while I was upgrading. It worked fine. I wouldn't recommend this, but just a heads up.