I prefer an old house that is renovated to a new house. Older houses generally have more character, larger rooms, higher ceilings, bigger gardens, much better build quality etc.
With a new home, a lot depends on whether the developer likes quality. Whereas there are some good developers around building houses that will be classics in years to come, the majority of houses built in recent years have poorer build quality to those built years ago. Many new houses are somewhat temporary in construction - structure designed to last maybe 80-100 years - whereas older houses are generally designed to last 100s. years. I dont like the trend in many new houses to use wooden external finishes. These will require a lot of maintenance in future years and will look shabby if not regularly attended to. I also dont like the trend to move away from solid concrete/brick internal party walls in semis and terraces. In spite of what the advertising may say about "modern sound insulation" - there is no substitute for having a thick solid wall between you and your neighbour.