Of course I have to include what I think is the most beautiful horse of all time: Zan Parr Bar. People know him primarily for cow-horse bloodlines:
He was just about as good as it gets: notice the angle on his shoulder, the trapazoid structure of his barrel almost jumps out at you, he is balanced (length of neck, back, and hip are equal), he has well structured hocks, his bottom line is almost twice as long as his topline and he has a smart head. Some people don't like a croup like his, but this is a matter of personal preference--I think it balances out his withers well and he looks like a horse I'd love to ride.
Here is the site of someone else who gets it. Yes, these are cow horses, not halter horses, but the majority of them are gorgeous animals with CORRECT conformation: http://www.oasisquarterhorses.com/sold_horses.htm
I especially like Pepto Chexx. He's a cutie (AND correct):
Again, no halter horse, but this horse is built right, so he's going to ride right. He has great feet and good angles to his legs, so he'll stay sound while at work. This is not rocket science.
Now let's flip that around and take a look at a halter horse that has poor conformation:
They are trying to halter this foal, but I bet you money that he's not doing very well. He has a straight shoulder, his pasterns slope way too much, and while it's hard to tell because he's not set up right, his hocks are way too weak, his hip is way too short and his throatlatch is very coarse. This horse isn't awful, mind you, but he is going to be hard to ride and will not do well in a halter class.
We're all on a learning curve here and I definitely need to learn a lot myself. However, making excuses for breeding junk doesn't help anyone. Study and learn so the horses you produce can go on to great things rather than end up on a long trailer ride to a Mexican slaughterhouse.