The question is where to start!
Our favourites in no particular order are....
Silverbank CC site at Banchory, on Royal Deeside. Handy for the many delights of Aberdeen and Aberdeenshire. Usual CC standards, all hardstanding pitches.
Balbirnie Park CC site at Markinch in Fife. Handy for Edinburgh, Glasgow (wee bit of a hyke but do-able), Stirling, Perth, Dundee etc. Easy access to the Fife coast. Mix of grass and hard standing pitches, also some non-awning pitches. Toilets immaculate though not exactly new. Lovely staff.
Yellowcraigs CC site at Dirleton near North Berwick in East Lothian. Handy for Ednburgh and most of central Scotland. Lovely beech on your door step about a 5 minute walk from the site. Mix of grass and hard standing pitches, grass not a problem here as it is fast draining sandy soil. Toilet block is palatial!
Edinburgh CC site, Edinburgh (!!!). Easy access to town via bus. Mostly hard standing pitches, only a couple of grass ones. Some service pitches. Nice loo blocks (if you don't mind pipped music!).
Gibson Park CC site at Melrose in the Borders. Site in the heart of historic Melrose. Galashiels, Peebles etc within easy reach as is Edinburgh. All hard standing pitches with some service pitches. Loo blocks are clones of the ones on the Edinburgh site minus the music.
Can also recommend Maragowan CC site at Killin, The Woods CC site at Alva, The Invercauld CC site at Braemar, Huntly Castle CC site in Huntly, New England Bay CC site in Galloway, Lidalia CC site at Newcastleton etc etc. Basically there isn't a bad CC site in Scotland!
I think you need decide which area(s) you wish to visit ... it is a big country you know!
Enjoy!