FA
Goljan (use his audio too...cannot stress this enough.)
BRS physiology (such a good book for solidifying physiology concepts)
HY Neuro (they seem to like neuro questions on step I)
HY Anatomy (this is +/-...if you use it, don't get bogged down with all the information...just focus on clinical stuff like what muscle/action gets taken out when a certain nerve is damaged, blood supply to the gut, etc)
Use USMLE world QB and possibly some Kaplan QB if you have the time. Take at least one official practice NBME half exam mid-way through your studying.
Not sure of the total cost for all those resources, but they paid off for me. Happy studying.