-Particle: These DEW beams have more of a kinetic impact than a laser, however, they are shorter range than a laser. Particle beams require a great deal of technology to work, like circular accelerator, which is similar to the "atom smashers" of current science, they are massive and require a massive amount of energy to work.
-Plasma: In sci-fi works, like Terminator and HALO, plasma is used for the main offensive tool, however, this works require that the ionized gas, normally hydrogen, is converted from slush hydrogen, via a laser, then fired down a barrel with a EM sabot containing the ionized gas until it reaches the target, and explodes in a shower of thermal and kinetic damage. Nice, but lots of steps...and EM sabot are not yet proven science. Plasma would make a nice futuristic flamethrower or short-range mortar. If plasma and the EM sabot were a possibility, then plasma would make a good DEW system for tanks. Plasma as the advantage of being a fire-and-forget system, not need to hold the beam over the target until the armor is penetrated like lasers.
Kinetic Energy Weapons?
Here is a link to a site devoted to OGRE and GEV RPGs
Link to a site about the hover tanks in Hammer's Slammers
Link to a fansite devoted to Renegade Legions: