Retail - Has 3 year warranty and the stock AMD HS/F
Agoga - OEM (CPU only, no HSF), good overclocking core (though I think AROIA is newer/better), no warranty (only reason to get it is overclocking, which voids the warranty)
So, if you plan on overclocking, you should get the AGOGA, since you wouldn't use the stock HSF and will void the warranty, anyway (although, if you're going to overclock, I would recommend the 1600+ instead). If you aren't going to overclock, and don't mind having a HS/F that is adequate but not great or value the warranty, then get the retail.