Not currently a gym member, but I've been playing with some exercises that I can do elsewhere.
Yoga.
Push ups, done ultra slow at wide hand spacing, on or off exercise ball.
Chin-ups, done from a staircase with overhand grip and a slow crunch at the top of each rep.
Dips, using the backs of chairs, again with the crunch.
Ab work, front and side, on ball.
I find the compound exercises to be quite draining, esp. when doing a few sets, and consider them meaningful.