Here is Top Prospect Alert's Top 15 Astros prospects, with a run-down on their season. Below is their ordered list, click the link for explanations.
#1 Jordan Lyles
#2 Delino DeShields
#3 Jonathan Villar
#4 J.D. Martinez
#5 Mike Foltynewicz
#6 Jiovanni Mier
#7 Ben Heath
#8 Tanner Bushue
#9 Rod Quintero
#10 Austin Wates
#11 Mike Kvasnicka
#12 Ross Seaton
#13 Tommy Shirley
#14 Vincent Velasquez
#15 J.B. Shuck