Buying a house is a highly personal decision. Let's say that you want to look into owning Seattle real estate. As you look through different neighborhoods and Seattle homes for sale, you'll find both newer and older houses appealing at some point. Picking between them is a matter of personal preference, but it wouldn't hurt to look at the pros and cons of picking each.
The great thing about old houses is that you can enjoy several things about it. Older architectural styles have more character and are more distinct than newer homes. The craftsmanship is nothing like newer homes are made with these days. There's a lot of details poured out on the construction of old house. The problem with that is that unless you modernized the major systems (HVAC, water pipes, etc) in the house, it would be harder and more expensive to replace. The phrase "they just don't make 'em like they used to" can really work both ways. For example, if the house uses an old heating system, there may not be too many people who will know how to fix it, and the parts would be really hard to find. There are old houses, however, which already have a modern HVAC system installed. Only the outer appearance of the house has been preserved. Asking about the major systems in the house would be a must when thinking of buying older houses.
Older houses can also have larger yards than new houses which focus mostly on larger houses because the lot area is typically smaller. Land is more expensive so lot sizes are smaller and most of the area is used for building a house rather than leaving open spaces for a front or back yard. If you opt for older houses, there are larger yards that usually come with it, which means that you'll have more space to play around with. If you're not very particular about the yard space but you absolutely need to have large closet spaces, newer houses could be quite attractive for you.
Older houses also give you the benefit of older, more established neighborhoods. If you want to live in a place where you want to be sure that the neighborhood will be more residential than commercial, then buying an older house in an old neighborhood would be best. Zoning changes are unlikely to happen here, much like an older person is set with his old ways.
Buying newer homes would mean that the homes would be outfitted with modern conveniences that people have come to get used to. It's also more likely to still be covered with builder's warranty. If you buy a newer house, it's less likely to need major repairs as well. You're not likely to be needing a new roof or HVAC systems right away. This isn't to say that new homes don't have their own repair problems, though. There's really no perfect house, and one way or another, there will always be maintenance to do.
It all really boils down to what you prefer and what you're prepared to do when dealing with repair needs in your home.