snowdon's a great run - my first marathon and loved almost every minute of it, except for the last downhill bit where i almost cried.
As for 'hardest in the uk' and all that stuff - it has to depend on the individual and the day. London in the hail, wind and snow would be harder than snowdon when the sunshines I'm sure
This Picnic run should be grand too - I came up with the name so I feel something of an affinity for it, though can't run as I have IM austria the next day....
They guy offered me a free place tho which I've not had takers for - if anyone wants it, let me know.