Personally, I've been taking it for many years, for many reasons. I am genetically predisposed to colorectal cancer and serious cardiovascular problems - both led to the death of many relatives and my father has been battling both for a long time now.
Since my adolescence I've also been a migraine sufferer, which is where I originally "discovered" Aspirin, because it helps lessen the impact like no other substance and over the years I found that regular preventive usage reduces the frequency of bad episodes to below 1/y, which is simply awesome. It's probably important to mention that I got the stomach for it, too, which is something that precludes many people from taking it on a regular basis.
With my anecdotal history in mind and weighing my person risk factors against the known complications (I dread ever being in a serious accident where blood loss becomes an issue), I have elected to take it every day.
Pharmacists are horrified, by the way. "Don't take it for longer than 3 days!" "Wouldn't you prefer Ibu instead? You should."