I like to crochet (used to knit, but since I taught myself to crochet a couple of years ago, I find knitting too slow!), do puzzles (complexity depends on how tired my brain is - after a busy day at work, a good old word-search is great for 'zoning out' on the train home!), read and watch TV. I've never been any good with plants - I had a plastic fern and it wilted - so gardening is not relaxing at all!
For total chilling out, I absolutely love a good coffee in the sun, with Fleetwood Mac's Albatross as my soundtrack - bliss.