Weeping Willow are wonderful to stand under on a sunny day, the way the light flits between the leaves as they sway. They're also one of the first to green in spring. I also like the Cracked Willow for the awkward, distorted shapes they form and the sound of the wind through their leaves.
Cherry are great of course at this time of year. I have a tiny cherry in a pot and it's one of the first things to bloom in my garden. Magnolia get props too for spring flowering.
Oak, because of how ancient they can get, the distinctive shape of their leaves, acorns, and the way they spread out and dominate any area they establish in.
Horse Chestnut. Childhood memories of hunting for giant conkers.
Yew. When they're allowed to grow into trees with their green needle leaves set against reddish bark. They can also live a very long time. There is a folk tradition in the UK of planting them in churchyards and cemeteries which are good places to find old ones.