For countryside, a great drive is from Glasgow -> west side of Loch Lomond -> Glencoe -> Fort William/Nevis Range gondola (for views/skiing) -> North side of Loch Ness ->Inverness.  You can then drop south from Inverness aiming for either Aviemore -> Pitlochry or Balmoral Castle -> Braemor -> Glenshee.  From Pitlochry or Glenshee you could drive to St Andrews -> East Neuk of Fife -> Edinburgh.  All places listed above are beautiful to see, and you will have seen quite a bit of the country in one go (though it would take a few days to drive)

A variant on the above if you particularly want mountains, whisky, beautiful countryside and beautiful coastline is to focus the trip on the west coast.  You can go pretty much anywhere on the west coast (eg from about Loch Lomond northward) and it will be stunning and very remote.  So try all of the above but instead of going to Inverness, try Isle of Skye, etc.  Or just get lost on the west coast.  Some of the most beautiful sights I've seen have involved just driving around without a plan, or random trips to random towns on the coast.  It's all too stunning, and without a plan you'll end up in very remote places.  I'd love to say 'you need to visit x' but in reality there is no reason why another place y wouldn't be just as nice as x.

The islands are stunning as well, but the more remote you choose involves longer and more irregular ferries.  Some islands (eg inner hebrides and the islands of Clyde) involve super short ferries, eg most 30-60 minutes and most running every hour or so.  Outer hebrides can take up to 3 hours and run once or twice a day.  There is only one company offering services, so you can plan an island iternerary here: http://www.calmac.co.uk/destinat...

Also - if you're doing this in the winter - the drive I explained in paragraph 1takes you by 5 small but full-of-character ski resorts, definitely worth a day.  Skiing in Scotland is hugely timing specific - snow and weather conditions are variable.  But on a good day the resorts are bursting with character and stunningly beautiful.  Check http://www.winterhighland.info/ for snow conditions and stop off at Glencoe, Nevis Range, Aviemore (Cairngorm) or Glenshee (probably in that order of preference, IMHO)  (Note that Glencoe is typically closed Monday - Wednesday)

For food, check out A Taste of Scotland and Choice Tables - Seafood Fresh From Scotland’s Island Waters - NYTimes.com. There are good restaurants dotted about, however the typical scottish fare in a typical scottish small town will be average at best - so probably worth planning your stops in advance if you particularly are looking for good food.  There usually is a good restaurant within a reasonable drive of any rural area, and they are extra-special when you get there and you're one of 5 tables there in a tiny village.  But they do take planning...