I would do a round trip. Go up to Bodmin and then head for the north coast on maybe the 3072 via Holsworthy to Bude, then down the A39 diverting to Boscastle, which will take you to Tintagel.
Then if you've got time take the B-road, the 3314, which will let you divert on the way to Port Isaac, to Wadebridge.
Then go A39 again & take the 389 & 3276 to Padstow, and if you've got time find St Merryn, and then turn right down to Constantine, which is a fabulous beach (but even in winter parking is

)
Then back on the 3276 coast road, as twisty windy uppy downy as any mini could wish for, with more huge views, to Newquay.
EDIT Before entering Newquay on this road you go past Trevelgue, home to the Riv Run.
BIG BLANK HERE because I don't know any more pretty coastal roads (usually belt down the A30 to Hayle).
Then either through or bypass St Ives on to the 3306 Zennor, Pendeen, St Just etc with more breathtaking views (er, if it's not foggy) to Land's End.
And come back along the south, through Penzance etc.
That's enough from me, and lots of tmfers actually live there and I'm just a longtime grockle. But I lived there for a bit and I love it.
The north coast is often wild and wet but here's calmer picture from my bro's house near Zennor
Edited by Teapot, 09 March 2010 - 05:28 PM.