I had to make some minor edits to the Blogger template used here anyway, so I decided to have a little monkey with the fonts. Here’s what you used to get: 
And here’s what you now get: 
I think that’s much better. Good old Helvetica! I don’t understand anything about typography at all, but I think that the latter doesn’t look as messy, perhaps because of the spacing being tighter. Interestingly the title actually takes up more space, because the bold font is heavier. Marvellous.
Supposedly serif fonts are easier to read for extended periods of time… but with a black background, Helvetica might work out okay.
My roommate is a typography freak. He can spot Futura a mile away.