Not really interested in your actual point size as it depends on resolution and font, but rather if you prefer larger text that is easy to read, or small text so you can overview more lines of code.
Personally, I keep bumping up the size the older I get. Is this something that you also have experienced?
Do your IDE support easy zooming the fontsize? If so, do you use it regularly?
I like large font sizes personally (12+). It keeps me from having to squint. Psychologically this also tends to make me think twice about writing extremely long variable/method names. It also makes me code a little more carefully as it's easier for people to look over my shoulder and see my code. :-P
Medium-small with more lines of code and good line spacing and syntax colouring. Never zoom font size, but did make switch from non-antialiased (BBedit) to anti-aliased (Textmate) and am not going back.
You get used to smaller fonts once you work with them for a while - I changed my resolution to a greater one a while ago and at first it was kind of hard to read, but then after a while you really start to enjoy being able to open a bunch of shell windows and your IDE without overlaying each other.
Anyway I think it's well worth it to use smaller fonts since you can see more code simultaneously.
I use the smallest size I can easily read. And yes - it get bigger from year to year :(
I agree with Kevin. I used to use really small fonts so I could squeeze a ton of text on the screen, but I would go home with headaches each night. I recommend using something that is big enough that you can easily read (~12 pt) as well as a color scheme that is easy on the eyes (http://idehotornot.ning.com/).
11pt Consolas, but only with Vista's rasterizer. I've found that even XP's rasterizer does quite poorly with this combination, though not quite as bad as Java's (pre-uN).
I don't really change my font size at all. I find that once I get used to a certain representation for source code, it's best not to mess with it. I made the switch to monospaced fonts a few years ago, and that was certainly an interesting experience. I felt half-crippled, unable to even read my own code due to the slightly altered format.
I find a mid-sized font (Monaco 12) serves me well. I use textmate on OS X, which makes it easy to adjust point-size at a whim (cmd +/-).
I like small minimally aliased fonts like Profont, beacuse they stay readable at small sizes, and I can fit a decent amount of code even on a 15" laptop monitor.
When I have my external monitor plugged in, I have it vertically rotated and bump up the font size a bit because the monitor is farther away from me; 22" high in vertical orientation gives me a good 130 line span in the editor :)
Smaller sizes with a high contrast, light text on dark background.
NOT white on black, though. That's insane.
Like others I'm using larger fonts, since getting on the plus side of fifty. Most recently I started using the Consolas typeface and have really enjoyed it. Fixed width indents well. The clear differences between lowercase L and number 1 and the letter O and zeronumber 0 for example also makes this a really good programming font.
12 point Monaco - tempted to switch to 12 point Consolas like I have at home. On a larger monitor larger text means I can sit back comfortably, see better, and run less of a risk of eyestrain. I used to code small, but at these resolutions (1920x1200) even 12 point is pretty small.
Speaking of which, why on earth is the text in this text box so impossibly small by default? It makes it killer to read.
Point size is a physical measurement, it shouldn't depend on resolution or font.
I don't go for small as possible, nor large as possible, but rather I find that there's a 'natural' size, where, if I go smaller or larger, I can't read it as quickly, despite it being completely legible.
As for zooming, if you think that's even remotely necessary, then you're setting it way too small. And in any case, in GNOME, you can just hold down the Windows key and scroll the mouse wheel to zoom in and out, no application support necessary.
I guess I'm still young enough to be able to go for the smallest font possible. In that category I'm surprised nobody has yet mentioned the Proggy programmer's fonts. I think they're great. Very small, and no ambiguities between the glyphs used for ones and els and ohs and zeros.
I've also found that the amount of text you can get on your screen depends a lot on your text editor and how it spaces lines. With emacs I can get the Proggy fonts so that there are zero pixels separating the descenders on one line from the highest ascender on the line below. For instance with these two lines:
gj
fl
The bottom of the top row touches the top of the bottom row. Sounds illegible, but in typical text such line-ups happen rarely. With this proggy/emacs combo each row uses exactly 10 pixels of vertical real estate. I haven't found any other editors that can get the spacing that tight and still being legible. Usually it's 11 or 12 pixels at the minimum.
12 point Consolas, using a variant of Vibrant Ink colorizing rules. I like to keep my editor full screen as well (Shift+Alt+Enter in VS). So much for the old < 80 chars per line.
I prefer using a medium sized font. Something that shows up and I can easily read from a distance of about 1 foot away from the screen. I use Courier New too, it just feels right.
I've been going with 14pt Consolas, but I have a 1920x1200 15.4inch screen (WUXGA+, I think...it was a free upgrade from the other option). I got it on a laptop 4 years ago and haven't had any issues, except I'm almost always zooming text on almost any website I go to, and some don't handle it too well.
That being said, this laptop is getting old. If anyone has any tips for finding a similarly high-res laptop, I'd be much obliged.
Larger than the default in most cases. 12pt to 15pt usually, and always a font with serifs. Except Comic Sans worked pretty good for a while.
I'm paranoid about confusing parenthesis for square brackets, commas and periods, and so on. I even have a bad habit that acts up now and then, from when i was very young, back in the days of typewriters (and dinosaurs) using lower case L for the digit '1'. Must have a good font where they look different!
If you're working in a IDE with sidebars on a 1280x1024 screen, then try Verdana 8pt.
Cons: It's variable-width.
Pros: It's readable and it fits a lot of text in a single line.