This is a lilac bush. It has been planted (by previous homeowners or by the original landscapers, I don't know) under a window on the north side of a building. Lilacs are genetically programmed to grow about ten feet tall, and the fact that they are planted in front of a window only four feet from the ground won't stop them. Note where this bush has been lopped off in various places to prevent it from blocking the window - a large factor in its ugliness.
The other problem is the amount of light that reaches the shrub. Because it is on the north side, between another (almost as ugly) lilac bush and a tree, it receives very little sunlight. All this shade has three effects: the bush hardly ever flowers, the leaves are unnaturally large, and the bush is always sending up big, long, suckering sprouts in an attempt to find some sunlight, further blocking the window behind it and necessitating severe pruning. After the spring growth, it eventually stops growing and then looks like a moderately tidy, round, but very boring shrub for the rest of the summer, until the leaves come down in the fall, leaving a hideous form for the winter landscape.
These lilacs are nowhere near as attractive, productive of blossoms, or healthy as they would be if they had been planted on the south or west side of a building. The constant pruning to prevent it from blocking a window isn't a chore to look forward to, either. If whoever planted this lilac had thought about the location just a little, they could easily have found something more suitable. A dwarf American cranberry bush (Viburnum opulus 'Nanum') would tolerate the shade much better, while requiring no pruning to stay below the window.
So before you plant, especially long-lived trees or shrubs, be sure to check all their requirements and that they match the attributes of the location you plan to put them in. Will they have the right amount of sun or shade? What are their moisture requirements? How tall will they grow? You can save yourself a lot of trouble just by matching the right plant to the right place.