I've only ever played with it, but Particle Illusions SE works well for adding explosions etc. For titling, I think you'll find Bluff Titler hard to beat at the price. Version 4's just been released, so that's something new for me to play with!
I have absolutely no experience with this product, but check out http://fxhome.com.
Their Effects Lab DV program lets you do particle effects, rotoscoping, light swords, etc. It sells for about $112 US. They also have a program called Composite Lab, which is used for green-screen compositing, or any multi-layer compositing, etc. The only snag is that these programs do not integrate into other editing programs. You would do the effects work in Effects Lab, render it out to an AVI, then bring it into VMS.
Again, I have no experience with these products, but I check out the submitted movies in their Cinema section on a regular basis. In particular, I enjoyed a movie called "It's Coming", and another, "Art of the Sabre". (do a search in the cinema to find them)