Oh man there's so much to see. I'll break it down by area.
North: The Highlands
Loch Ness (my families castle ruins are just south on Loch Oich)
Dufftown
Ullapool
Glencoe
Glen Finnan (where the Highlander was from)
Cape Wrath (this is an allday trip)
Middle:
Stirling and Stirling Castle
Edinburgh and Edinburgh Castle
Linlithgow Castle
Near the Kincardine bridge in Airth is the Pineapple (cool building)
Kinross
Culross
Largs on the west coast
Glasgow(haven't spent a lot of time there but it's the biggest city there)
Dundee
St. Andrews
South:
Dumfries
The Midlands
Hadrians Wall (just across the border into England)
Cheers,
Scotsman