TrueBeam

Maybe more in the “less mainstream” category rather than exotic, but I love ColorFabb varioshore TPU. I really like the texture and slight squishiness it gets at 220°, also floats. I also use it in lots of places where I don’t really need a semi flexible, it’s surprisingly handy.

For exotics, as in “need to scour the internet to find”, eSun ePC is a personal favorite. Prints very cleanly at 270°, looks great, very little warp, super durable. Nasty fumes, though.
Edit: a lot easier to get hold of now, must have been a production hiccup last time I needed some.

Yes, it’s soluble in acetone, quite similar to ABS.