I don't have a huge number of minor tunes in my repertoire, but I love the ones I play. They add so much partly because of the variety they bring. If you use diatonic instruments like melodeons, keys are limited and it can get pretty boring if everything is in Gmaj or Dmaj.

The morris tune Idbury Hill is a good one.

I play one of the tunes from the Thomas Hardy collection called "Dribbles of Brandy" that is minor.

I currently live in the US, and play some of the American Old Time Tunes. In that tradition, there are some great ones such as:
Cold Frosty Morning, Elziks Retreat, Pagan Rite, Bank of Flowers.

There are thousands more (reminds me of a song!) of course that I don't currently play. I am working on that.

Variety is the spice of life.