I worked in biomedical research for a while and few things seem to trigger controversies like Aspirin does. Many MDs believe it's evil and don't condone its use for pretty much anything, but on the other end of the spectrum some medical professionals seem to self-medicate with it religiously.
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."