Off of the top of my head: CLOCK-Pro [1] - an approximation of LIRS [2]

It's quite popular, I remember that MySQL and one of the BSDs use it.

[1] http://www.cse.ohio-state.edu/hpcs/WWW/HTML/publications/pap...

[2] http://www.cse.ohio-state.edu/hpcs/WWW/HTML/publications/pap...