whats the less eye tiring font?

There's no way of stating this definetely.
Some people have a hard time seeing small fonts, like this on the other hand some people find fonts like this hard to read. This is based strictly upon the size of the font.

Most people find a font size of 11 points easy to read from a distance of about 1 1/2 - 2 feet (45 - 60 cm).

Other aspects that need to be taken into consideration, are font style, foreground colouring, and background colouring.

I was basically asking for font style

I use Verdana 10pt in 1600x1200 on a 20" LCD for Query/Channel windows. Tahoma 8pt for status windows.

Both are easy to read. Neither are fixed-width so if you rely on spaces to line stuf fup, they'll dissapoint you.

Courier new is nice.
Also, i think the best font on the web, look for ProFontWindows
And get the newer one and have cleartype set.

Top pic = Courier new 8pt
Bottom pic = ProFontWindows 9pt

For IRC, I find Verdana easy to read. However, it isn't a fixed width font, so if you're looking for that, you'll want to use a different font.

are fixed width (monospaced) fonts considered more comfortable to the eye?

I definitely think they are.
It's easier to read as all the characters are the same size, so in effect if you go down the scientific route, your eyes have to do less work than looking at a scribbly all over the place font

I find clear proportional's easier, more like clear hand writing.

Thus why Tahoma and Verdana are what I use.

But every body is different.

I read documents (on paper) in 6pt Verdana, so am used to it.

By the same token, I work using terminal sessions using fixed-width fonts all the time.

It all ends up with what-you-are-comfortable-with.

Exactly. Try them and see what you prefer. Everyone will have different preferences for this and other "what's better" questions. The best thing to do is to just try them and find one that you like.

I like Microsoft Sans Serif (bold-11pt) for some channels, again a non-fixed width font. I set my fonts on a per channel basis though so i still have fixedsys-9 as default.

btk