Computer Modern is the family of typefaces developed by Donald Knuth for TeX. It’s so good-looking that some scientists do research just so they can write it up in Computer Modern.
The cm-unicode project compiles versions of the Computer Modern fonts in a few formats, including TTF. I’ve run them through codeandmore’s @font-face kit generator to get all the weird formats that the various browsers insist on.
I’ve put up a page containing examples of each face in use and links to packages containing everything you need to use them.