Thinking Aberdeen personally, love their beach and they have really cool nature to explore but really depends what your after. Aberdeen is ranked 17 in UK for Law while Dundee is ranked 28, but that's only if you care about rankings, I've also heard employers don't really care between the two anyways. Dundee is a beautiful city, its smaller and closer to Glasgow/Edinburgh, I've heard the night life is quite mixed though, its mostly bars and theres about 1 club.
Aberdeen is bigger and has more things to do, I've heard it has a better night life, much quieter than cities like Glagow but more lively than Dundee. Both citys have their ups and down, you should really go visit and see what you like