Amelanchier lamarckii; not exactly a tree, gets up to 13 feet usually with more than one "trunk", blossom, bright red leaves in autumn

Betula jaquemontii. A birch with pure white bark. Try a multi-stemmed plant and surround with Ophiopogon planescapens nigrescens (!sorry) a black leaved 'grass' ( a lily member actually). They have it like this in the winter garden at Wakehurst place. Or Prunus serrula. This has lovely shiny mahogany coloured bark that peels. Mine always gets comments. Don't go for a pink cherry as their period of interest is only 2 weeks.

then there is the magnolia and many of the sorbus species [rowan, whitebeam etc flowers and berries]

Don't plant a flowering cherry as after a few years, the roots come to the surface and make mowing difficult

Agree with Andrew - not to mention the sucker growth...

Judas tree (Cercis siliquastrum).