On just any topic be it on real events or fictional ones? I find myself researching a lot of things mostly in the fictional area's on Wiki most of the time. The moment I don't understand something I go Google it and try to find a wiki page on it. If its one thing I learned in school its "never stop researching." I feel its one of the most valuable things I've carried with me throughout life.
If somebody so much as mentions a word or term I don't know, I usually pop open Wiki or a dictionary site. Aside from that, I do a lot of self-motivated research on mythology, especially celtic myth, and lately mythopoeia as well. Game theory (No, not the show) interests me as well, but it's harder to find good articles on that.