In addition to hearty agreement on the M47 (especially), the M109, and the Soviet SAMs, I'd add:
Centurions (Mk3, Mk5, Mk8, Mk13, plus versions of the Israeli Sho't)
AMX-13 (the Heller kit is impossible to find, in additon to needing much work)
Hawk missile battery
WWII era US construction equipment (dozers, graders, earth movers, dump trucks, tank trucks - tons of diorama potential)
M2 White half-track
Brown Water Navy vessels in injected plastic
PBR Mk I
PBR Mk II
Monitor
Swift boats
Alpha boats
Tango boats
CCBs
Zippos
Armored LCMs
STABs
MSSCs
Air boats
FJ-2 Fury
FJ-3 Fury
AD-5/A-1E (modern kit)
Super Frelon helicopter
Sterling bomber
i could probably go on all night....
Steve