I, like most others here, will put practically everything into it. Mine has an eco setting that actually tumbles with cool air, so gets rid of the problem of shrinkage. The only things I absolutely have to iron afterwards are DH's cotton shirts - evrything else can get by with a smooth-and-fold, if needed. And if I do want to iron it, it takes a fraction of the time.
(Yes, I'm wierd, I like ironing. It's a good excuse to watch crappy telly at the same time but still feel like you're doing something constructive )
If you've got one of the sensor dryers, you can tumble pretty much anything - it will adjust the temperature so it doesn't overdo it (for example, mine has a button you can press for delicates)
Definitely better than a damp mouldy house - now outdoors drying is effectively over for the year, we would be screwed without our tumble dryer - we are in an old Victorian building with no cavity wall insulation and have terrible problems with condensation and mould.