In MAME, you can specify a specific font for UI menu or change the look of the default crosshair. Here a some starter files below:
Starting with 0.107, MAME added support for different fonts in the User Interface (UI) menu. Simply take any .BDF font, name it to ui.bdf, place it in your MAME directory, and you are good to go.
As a mainly Windows, user, however, I had never heard of BDF fonts (they're an X-Windows thing as far as I can tell). Anyway, I found this neat little program that converts TTF fonts to BDF, called otf2bdf. To make the font show up decent enough, you need to make sure to convert it to a big enough point size. I used the following commandline when converting the ones below:
C:\>otf2bdf -p 48 fontname.ttf -o ui.bdf
Below are some of the ones that came out half-decent. Just click on the pic, and unzip the file to your MAME directory. I add more when time becomes available, or when someone submits a cool one.
(Thanks to T0M for Century Gothic, Scoops for Consolas, and startaq for Nostalgia Four)
UI SYSTEM FONT
Starting with 0.141, MAME added support for using system fonts installed on your computer. Now, in addition to using BDF fonts, you can use most any font already installed on your operating system.
In your MAME.ini file, you can specify which system font to use under the option -uifont. (e.g. -uifont Arial).
Note that if the font specified cannot be found or cannot be loaded, MAME will fall back to its built-in UI font.
You can also define your own crosshair in games that use that feature. MAME already has its own generic crosshair built-in; these are here simply if you would like a variety.
Thanks to Derrick Renaud, as of version 0.131, you can now define crosshairs for specific games, and change your crosshair through the in-game menu. Download the file below (updated by Derrick), and unzip it to your \crsshair directory (this setting can also be changed in your mame.ini file).
Files named "cross1.png, cross2.png, cross3.png, cross4.png" in the main crosshair directory will be the default for player 1-4. You can also use the in-game menu to change the crosshair; this setting is saved in the game's individual CFG file.
You can also create a sub-folder within your \crsshair directory to create a unique default crosshair for an individual game. Some examples are included in the below file.