Many gardeners would most likely nominate Spring as their favorite season. For me, it's Autumn, mainly for the cooler weather and the colour of the trees.
These caught my eye today.
These Ornamental Pears, Pyrus calleryana 'Capital' have been planted along the fence line of a customers property. They grow about 10 mt high but only 3 mt wide so are great for restricted areas, giving height without broad spreading width. They feature white flowers in early spring, with the foliage turning yellow, orange, red and purple in the autumn. They are also fast growing. In some ways these have been somewhat over planted in the community, but for good reason as Pyrus have many virtues.
The only drawback in my opinion is having to clean up the fallen leaves in autumn. The foliage also takes a long time to break down unless shredded.