I have 2 pads I like a lot and my horse does too. The one I use the most is a Skito pad and the other is a Cavello Old Mac pad. Both are pretty thin. I like the Skito because I can take the inside out and wash it. Both of these pads are kinda expensive in the $100 range, not the top end Saddleright but good pads.
"Until one has loved an animal, part of one's soul remains unawakened..."
- Anatole France