Same here. The letter-forms themselves look good, though. Maybe if the spacing between the letters were narrower? The kerning (that's what it's called, right?) seems unusually large, particularly for a fixed-width font.

Well, trisk is very legible for me at normal reading distance where e.g. proggy or profont feel too squeezed and slightly too small. But ultimately it's also a matter of taste, ofcourse.

Generally screenshots can hardly do programming fonts justice. You have to load them into your editor and try them out on familar code.

Most of the fonts showcased on that page look perfectly fine to me from the images. I only learned that I can't bear an anti-aliased font and about my various gripes with the other fixed contenders because I once went and tried all of them for at least a few hours each.

Agreed. Aside from a few major variables (fixed-width or variable-width, anti-aliased or no, weight), and ruling out fonts with obvious flaws like making 0 and O look too similar, it's largely a matter of taste.

I've found that some fonts look much better as light text on dark backgrounds, or vice-versa. I use terminus (http://shenani.gen.nz/~scott/img/terminus-sample.png), but something about it doesn't look right to me on a light background.

Indeed. I found the choice of font less critical on light backgrounds but that might be because I'm a white-on-black fanatic and can't bear a light background for long anyways - regardless of font.

But I, too, noticed the difference and I don't think it's just subjective. Black-on-white is generally easier on my eye in the short-term but for the long-term (e.g. coding sessions) I strongly prefer white-on-black because staring at a mostly white screen for extended periods of time makes me dizzy.

Yeah, I know some font rendering technology specifically draws dark-on-light-bkgnd differently from light-on-dark-bkgnd, though I can't recall where I've seen it, or the details ...