My "dream" trail saddle (with a traditional tree) is a Hope trail saddle. They're pricey, but I just love the design and concept. A friend has one, but it's too small for my hiney, so I have not ridden in one. She and I like the same kind of "feel" in our saddles, so I'm sure I would love one.
The Hope Saddle is the Ultimate Trail Saddle
However, my favorite trail saddle that I have ridden in is my Bob Marshall treeless saddle. I LOVE IT! Very comfy, fits all but the WIDEST of horses, light weight, and looks good too. I have the endurance model, but with a taller cantle w/cheyenne roll, and tooling. I bought it for $1,000 used and it was well worth it! Because there is no tree, you do need a good pad. I use a
Skito Treeless saddle pad and
ThinLine western pad under that. I am a heavy rider (250 lbs), so I like to double pad. If you're not heavy, then just the Skito is enough.
Here's my mare and saddle, shortly after I got it (April 2007).