It seems that these days, with people being more open and such, there are a lot of people that are more openly fans of shows that aren't aimed at them. There's the My Little Pony movement for example, or the 13 year olds on first person shooters. How about you?
Since I'm way younger than 40 I do get the odd questioning look when I say I like Columbo. But I love it. XD It's so entertaining, and puzzling in a way different to most mystery series, in that you know who did the crime; the mystery is how Columbo's gonna catch 'em. I also like Jeremy Brett's Sherlock Holmes series.
I also sporadically go through episodes of Ranma 1/2. XD; It's totally daft and not serious at all and just fun. And it has really catchy music. \o/