I guess my most often used is IF, ELSE, ENDIF. The most fun to tinker with is the particle command set, but the most constructive command of all is sync - where would we be without it?
My favorite command though, is a little handy function i've written myself, gameSpeed() damned handy, not only does it prevent that ever so often amateur mistake of games running six billion times too fast on my PC but also meens those on slower PC's can play my games at the same speed as those on a fast PC, just not as smooth.
I so wish that more programmers would at least include a frame rate inhibitor in their projects, even if they don't allow for older machines. Imagine the difference on my latest project that runs at 200fps on my Bro's machine, and 600fps on mine - 3x too fast to play....? Now multiply that by whatever speed machine's we'll have in the summer...
Pneumatic
Pneumatic of Xev@EQ
God made the world in 7 days, but we're still waiting for the patch.