Looking back over the last century, it's interesting to note that some consorts stand out, revealing perhaps what makes a good consort - and what doesn't!
UK - Although most would think of the Elizabeth, I'm not sure how much of that is due to what happened before (in the abdication crisis) and after (as Queen Mum) she was Queen consort. Certainly her steely character was of great support to her husband during the war. Queen Mary was probably equally as important during George V's reign.
Romania - Queen Marie: glamorous and artistic, charismatic yet profoundly dedicated to serving her country and a real player in the politics of the post-WWI era.
Belgium: Astrid a beautiful young mother tragically killed.
Monaco: Grace - beautiful, glamorous and charismatic, very active in charitable work and perhaps the archtypal fairytale princess.
On the negative side, Alexandra of Russia and Frederica of Greece are perhaps the two most villified consorts of the C20th: aloof, interfering and anti-democratic.
Prince Claus is probably the most successful male consort of the last century.