If you never go off-road, a cross bike is suitable. Personal experience is important. Proper initial assembly is the key to bicycle enjoyment and comfort, and this is often an indication. Check the bicycle warranty - most bikes have a lifetime frame warranty. Parts warranties usually last one year.
Some shops extend parts warranties.
Make sure you look closely at the parts. Ask the salesperson how the components rate. Reading a few bike magazines will give you an idea. Often department stores or mass merchants will put good parts on a cheap frame to make the bike look like you're getting extra value. When you need replacement parts, it's great when you get back on the bike right away.