That's a good point. I don't really have any hard information on which is more dangerous in terms of ulcers. I find conflicting information online. One thing is for sure: you should NOT take either aspirin or ibuprofen on an empty stomach. Always eat something first.

I tend to lean towards aspirin for a few reasons. It's older (100 years versus 30 years old) so we've had more time to figure out what other side effects it has, as well as interactions with other drugs. The blood thinning effect reduces the chance of heart attack or stroke (while it's in your system), which is always nice. There are some studies which seem to show that aspirin has anti-cancer properties, but I'm not sure if I believe them, because they have not proposed a mechanism of causation. Finally, ibuprofen seems to be sold in higher doses in general and have a more intense effect, which isn't really want I want. I just want something that does the minimum most of the time.