I suspect that ballistic weapons would still be the norm for ground combat. Lasers have problems with accuracy and dissipation, and plasma weapons would be very dangerous for the user in the event of a malfunction. They'd probably be very advanced though - small caliber (perhaps 3-5mm or so), with explosive and/or armour-piercing tips, fired by magnetic fields - in essence, small railguns. You'd have higly accurate, long-ranged, powerful weapons, and the ability to carry lots of ammuntion, possibly of different types to suit the situation at hand.
There could be special weapons as well, though - plasma area-suppression weapons (like really nasty flamethrowers), and probably laser-based anti-armour weapons (like a big sniper rifle).