I don't what's the correct term, but you get the idea. Instead of using unrealistic sprites, why not real particles? It can add realism in the action, like bomb explosions, smoke, dust, missile/bullet trail, metal spark, lightning, blood splatter, casting magic effects, fluids, etc. There are so many possibilities.
I'm not into technicalities but it can eat alot of graphic processing power, so maybe we can also customize the effect thoroughly.
This is the only decent effect I found (seriously I don't know the correct word to search!)
http://youtu.be/lNMfEyFFNHw
Just imagine the realism of the scene!
