People who come on my tours often ask me what I would recommend to do in Aberdeen, especially if they are only here for a weekend and need to prioritise what they are going to see. So, for your delectation, here are my (completely biased and subjective) views on what you should in and around Aberdeen.
In Aberdeen
I always say to people visiting Aberdeen that they should check out the old fishing village of Footdee near Aberdeen beach which is full of charming old fishing cottages and worth a wander around.
Aberdeen is also quite rightly noted for its parks - Duthie Park and Johnston Gardens are my particular favourites.
Aberdeen Maritime Museum is a free museum all about Aberdeen's long relationship with the sea and is located right in the city centre.
Around and about Aberdeen
Even if you are pressed for time, I'd make an effort to visit the countryside around Aberdeen - one of the best things about this city is how easy it is to get to stunning, make-sure-you-see-this-before-you-die landscapes.
Some of the most beautiful scenery in Scotland can be found in the nearby Cairngorms and Royal Deeside.
Dunnottar Castle is a must-see (full disclosure - I did use to work there so I am biased). It is a beautiful ruin set in a stunning landscape with an incredible history that includes William Wallace, Mary Queen of Scots and the saving of the Scottish Crown Jewels. It is very easy to get to even if you don't have a car - the X7 bus goes from Aberdeen city centre to practically the castle car park or you can get the train to the nearby town of Stonehaven and walk the coastal path to the castle.
Stonehaven is a nice place to walk around too with the best fish and chips and ice cream in the area and some lovely walks.
If you aren't castle-d out, Drum Castle is a surprisingly comfortable, family home sorta castle. At the moment since Aberdeen Art Gallery is closed it is showing some of the collection there, with a particular focus on Scottish art.