pSX emulates the Sony Playstation, pretty much everything is emulated (to my knowledge) and most games run perfectly. It runs under Windows and Linux.One thing that should be noted is that pSX DOES NOT use plugins.The emulator is completely self contained.
The emulator has been designed to be as easy and unobtrusive to use as possible -- in most cases you will not need to configure anything to use it (except maybe the controls).
Install pSX 1.13 on ubuntu Lucid/Maverick
Download deb packaged from here
Please also note that lib32gtkglext1_1.2.0-3.2-amd64.deb (included in amd64 compressed file) must be installed for 64bit/amd64 systems. This is not needed for 32bit systems.
NOTE: While running, due to a conflict with pSX and pulseaudio, pulseaudio is disabled while running pSX. This may make any program using it crash and will probably make the mixer/sound volume control unavailable while pSX is running. It should return to normal when pSX is closed. If not, close any program currently using sound. If that doesn't work, hit alt+f2 and type in "pulseaudio" (without quotes).
If the mixer does not start up next time you start Ubuntu, add the pulseaudio command to the startup applications or to /etc/rc.local