Marks says:

If you are looking for 'Big Country', then getting up to the North-West corner of Scotland is the thing to do. Its not always pretty, but it can be awe inspiring, inspirational, scary or completely insane depending on where you are, the time of day and the weather. I tend to suggest the map here: http://www.taste-of-scotland.com/mapfull.html as being a good trip organiser.

I'd suggest basically the same as Nick, but I would /definitely/ include a tour of as far north as Ullapool - and a little bit further at least - and taking the ferry across to Stornoway on Lewis, Northmost pat of the Outer Hebrides, then come down to Skye via the Tarbert-Uig ferry.

If you do want to spend some money, try to see if you can get a night at the Altnaharrie Inn, opposite Ullapool. Tel. 44 (0)1854 633230. 8 rooms, access by private launch from Ullapool harbour. This is a popular place for very wealthy people (eg rock stars) to get married. If you can book it, keep it a surprise - I'm assuming you're travelling as a couple here, as this a /very/ romantic setting. North of Ullapool, you NEED to take the 'little mad road' north of Ullapool to Lochinver via the coast starting at Drumnunie (spelling?), rather than the main road that goes via Inchnadamph. Car hire: something sporting if at all possible, and you'll thank the lord that made ya! Exercise-wise, you can climb Stac Pollaidh (Stack Polly) from this road. I used to use Stac Pollaidh as my measure of fitness when I lived a few miles north of Lochinver.

Ask Neil for some suggestions about where to visit in the Western Isles. My Top Tip is to go to Harris and stay a night or two at Scarista House on Harris, overlooking a fantastic beach - http://www.scaristahouse.com. We were there last year - good hotel, nicely lived in rather than stuffy. Fantastic dinner with good wine cellar followed by a midnight walk on the golden beach, watching the sun set over turquoise sea.

On Skye - there's loads to do depending on weather, fitness level, time of day and hangover status, assuming you like walking. Avoid staying at the Sligachan Hotel if at all possible - great location, lousy management. Food: The Three Chimneys is Skyes 'destination' place, but has become a little formulaic recently IMHO. That said, the formula is a very good one. http://www.threechimneys.co.uk/ The Cuillin Hills hotel in Portree is getting quite good according to my local spies...

I have not visited Orkney/Shetland so I'm not going to say anything about them.