Per request..
#1. I find the background really distracting. The subject matte itself seems a little plain as well. I think I see where you were going on this one, but personally all I see is the back of a horse's head.
#2. Like it much better. The top of the frame seems to be lost, with no real color to speak of, and the subject is really symmetrical, but it seems to work for me.
#3. Your lighthouse looks like its falling over, and your lake is in danger of draining. I would have tried to ge this one first thing in the morning, or at dusk rather than in the middle of the day, but sometimes you have to make due with the schedule presented.
All in all not bad. I probably couldn't have done any better. :thumbup: