I have the #2 pick this year. Our league is 20 teams, and our prospect roster is only 3 deep. (You can exceed 3 by trade, but must be at 3 before the prospect draft each year.) If you keep 3 prospects you get 0 draft picks, keep 2 you get 1, etc.
Finally, once a prospect has obtained 150 AB's or 55 IP's at the MLB level they lose prospect status, and must be kept on our MLB roster. We get 9 keepers each year.
What this basically means is that longer-term prospects go down in value, as do those who develop slower. So top-end prospects and high-risk/high-reward prospects are more valuable, as are guys who will make the majors sooner. I try to avoid guys still in rookie or Low-A, unless its a cant-miss guy. (I wouldn't skip Harper for example, even if he takes 3-4 years.)
My only current prospect is Mike Moustakas.
Harper (99% sure he goes with the pick in front of me)
I have 3 picks this year (picked up an extra in a trade), one of which is the 2nd overall. Whats my target list look like?
I'm leaning towards Teheran as my 1st pick, but have no idea who to gun for after that. Trout? Lyles? Hosmer?
Edit: I guess I should mention that we are a roto league, standard 5x5 except AVG is replaced by OBP. So those nice high BB guys are even better for us.