Weight-assisted dips/pullups. I don't have the strength (or have too much body fat ;-) to do dips or pullups, so doing this with part of my body weight compensated still lets me hit this motion.
My abs never went anywhere until I started training them with weights. I like the Nautilus ab machines, particularly the torso twister and the chair. I've maxed 'em both out so I guess I have to find some other ab challenge...
Cable work on the universal, specifically tri pulldowns, lat pulldowns, and rows. I prefer DB rows but mix in the cable rows sometimes. I don't know if cable work counts as a "machine".
Nautilus Super-Overhead. Is there a corresponding free weight movement like this one? I find this is great for the last movement on back day for some more lat work.