Have you thought of starting Yoga or Tai Chi? whilst it can be a demanding workout, it's not fast paced...and it's very good for emotional and physical wellbeing...Pilates, I believe also falls into that category
The Fighting Fit, Fighting Fat one is really easy, and the first section, plus warm up and cool down can even be finished by my seriously unfit and asthmatic friend...! It's Harvey from the Fat club programme...
Also, ditch the clock, lol, and just go through it....sometimes you ahve to go against your inner hold back...and push yourself just that little bit extra, if you know what I mean!
Also, you mention dancing...maybe starting dance classes or getting one of the dance execises dvd'd would be somehting for you.
Another one that is pretty good but easy and not to tiring is Jade's Shape challenge...