I've purchased a few HF hammers that I haven't used yet. I was suprised that after I scoured all the hardware / home improvement stores I realized that HF seemed to have the better selection for blacksmiths...
Anyway, my favorite is a light (1.5?) pound ball peen that was machined by my father as a gift for my granddad. My dad worked as a tool and die maker most of his professional life, and when he first started taking machining classes he made a hammer for my granddad. When my granddad passed away, my father found the hammer, unused, in a drawer in his shop. He gave it to me when he found out I was getting into blacksmithing. It has a beautiful purple color to it from the heat treat. The faces of the hammer have lost the color though since I've been using it. It just seems really special to me. I used it recently on a gift I gave to my sister. I tend to use it for finishing work or on smaller stock since it is a bit light. Last night I used it exclusively on a holder for a shower head.
I'll see if I can't get a pic posted of it.
All my other favorite hammers belong to other smiths :)