I like hydrangea, but not sure the branches will die during winter or not. also please recommend some flower shrubs that will not die in winter so new leaves will grow from the old branches in spring

Hydrangeas are typically shrubs, but, depending on the climate, some hydrangeas will often die back and others won't.

In Ottawa, the big-leaf hydrangeas (Hydrangea macrophylla cvs.) are the ones that are tender. In a good winter, they all come back from the branches. In a bad winter, not so much. Plus some are tougher than others. The advantage to the big-leaf hydrangeas is their colour selection.

Hydrangeas arborescens is a far tougher hydrangea and the most well-known one is the Annabelle. It's good and tough and comes back every year. Drawback - white only.

The last common type of hydrangea is the Panicle Hydreangea (Hydrangea paniculata). These guys are also tough but they don't have the round ball-type flowers. Instead they're tapered and pointy, hence the panicle name. PG is probably the most common one. They typically all start flowering white but their flowers age to pink and then often to brown.

Other hydrangeas, like the oakleaf, are quite tender and die back each year (unless you got a really good spot). They're leaves are really nice and great fall colour, but they rarely flower again since they can't suffer die-back in order to flower.

Hope that helps.