RB and I decided to build raised beds for the many benefits they bring: they prevent you trampling your soil, make it easier to maintain quality soil over time as you only manure where you grow, keep the earth above ground warmer, and eventually look great, which will motivate me to get out and weed.
If you are DIY-capable or know someone who is, I suggest building your own as it is significantly less expensive than purchasing ready made ones. We plotted out our patch and have created roughly 1.5 square metre boxes – the largest possible size allowing us to reach to the centre (we both have long arms!). Here is RB building one of our 12 raised beds.
And here is the finished product in situ.
The Modern Gardener 
Love the raised beds. Are they decking joists??
I created our raised beds out of a very similar timber!
http://ryans-garden.blogspot.com/
Ryan
Hi Ryan, they sure are joists!
I am so happy with my raised beds. Sure makes for easier gardening.