I'm an Olympus fan, but I wouldn't recommend an Olympus SLR if you just want a bit of fun. They don't have as many lenses and accessories as Nikon or Canon.
If you want digital quality and have just under £20,000 lying about then take a look at this 39 mega pixel monster!
http://www.robertwhite.co.uk/hasselblad.htm#LabelH3
I wonder if this will be going to the moon like its predecessor.