vlad, without a doubt in my mind. short of having a nagging hammy or frank robinson deciding to pull a felipe alou and protect him, he's a veritable 40/40 threat who is fully capable of batting.330 and a near-lock for 100 runs and 100 rbi each year.
a-rod gets you more power #s (hr/rbi), but vlad's been putting up vlad-type numbers for 4 straight years, two of which with the steals... and he generally doesnt miss games either.
so i'd rank 'em like this:
bonds before a-rod because he's at a point in his career where he can put up special #s (hitting .400, hitting 60+ HR, etc)