The East Neuk of Fife is just gorgeous. Lovely white painted cottages, beautiful beaches, wildlife galore (including seals and dolphins). And, it's the driest part of Scotland (though that doesn't mean dawn to dusk sunshine
) Properties are expensive though and can be viciously so if there is a b ig golf tournament on at St Andrews! West Wemyss and Lundin Links cheaper than Elie or Crail or Anstruther.
Further along the Fife coast towards the bridge there is Burntisland, Kinghorn and Aberdour; again glorious beaches but holiday properties are scarce. I know because my family are in Fife and we always struggle to find somewhere to rent. There is a massive caravan site between Burntisland and Kinghorn overlooking Pettycur Bay, if static caravans float your boat. We stay there sometimes as it's cheap and cheerful.
Argyll and Bute was lovely too, we were near Tighnabruaich. Gorgeous beaches and empty of most people, and cheap as chips even in high season. Lots of driving required though.
Anywhere around Fort William, but lots of rain and midges.
Portpatrick and surrounding area in Dumfries and Galloway is lovely too. Portpatrick is really pretty. But again, it's a drive and half to get there.
South of Edinburgh is good too, lovely beaches at Longniddry, Aberlady, Yellowcraigs.
Ach, getting homesick just thinking about it all.
I'm surprised at the reviews of Skye; it is fantastic, mountains springing out of the sea, fantastic wildlife, loads of history...but yes, it rains and the midges are utter bastards.