Here is a list of a bunch that are referenced in the code. Many of them are situational and cranky, some might not work at all anymore, and the list may not be complete:
If anyone digs up any -more- particles, or gets a better idea how they can be attached to things, I'd also like to know as an aside. I've been banging on the whole idea for a while, but beyond attaching things @impact and @entity, or using ParticleOnSpawn I have limited options.
And I'd also really love to find the proper names of the explosion particles. As is I can only use them from an actual explosion, but I'd like to use them in other situations. Particularly Explosion.ParticleIndex "6", which is a big black cloud of smoke.