It depends on the situation, really. Most of the replies to this thread seem to assume that you are getting something for a special lady, but it could just as easily be your mother, cousin, a special guy, or something else completely. We don't know the occasion either, so it's hard to give general advice.
If you're taking someone out for the first time, bringing flowers and/or candy is ok. Candy can be hit or miss, depending on that person's tastes, so unless you have a pretty good idea of what exactly they like, skip the candy and just bring some flowers. They do require a little bit more work to take care of (the recipient has to find a vase, fill it with water, cut the stems, etc.), but they look and smell nice for a while and I don't know anyone who doesn't like getting flowers (not saying they don't exist... I just don't know any).
If this is someone you've been seeing for a while, or just someone you have known for a while and you want to get something nice for them, it is far better to get something that will last longer than either flowers or chocolate, as well as something more personal that shows you have taken the time to really get to know them. When my boyfriend and I started dating, he found out that I had a dismally small music collection and he started to burn CDs for me. We still share music now... it's just one of the ways we communicate.
Hope that helps even a little bit! Good luck