WTK: Best Slot-A CPU for the buck!

[mjs22]

I am looking at upgrading my 650 Athlon CPU...I want to know what is the best CPU that I can buy for the money!

 

[novice]

memman.com has this available:
AMDAthlon K7 850 128K Cache (Heatsink/Fan Required)(OEM) 133.00
This would seem to be a pretty good upgrade for the $. Not too sure how it would compete with the socket A Thunderbirds, though.
Chuck