Here's my contribution to this thread:
The first horse is Prince, a 17.2 black Clydesdale gelding that lives a few miles away. Nice horse, not a slouch by any means, and very comfy to ride.
The second horse is Bracken, another 17.2 Clydesdale that I shared for nearly a year. Great fun to ride (cantering him was like sitting on a rocking horse!), and he quite liked jumping!
The third photo is taken from Prince, with another Clydesdale (Mel) up front.
The fourth is the last horse I shared, Mouse, who I shared for a wee while this year. And more often that not I rode him bareback!